Prechecks fails when using multinode deploy using a single node and haproxy disabled

When using deploy with a single node, it is needed change the var kolla_internal_vip_address: pointing to node ip address.

And in this case, the prechecks process will fail, because this Ip address is in use.

Steps to reproduce

1 - Choose stable/mitaka branch and use the inventory as follow

======================================================================

# These initial groups are the only groups required to be modified. The
# additional groups are for more control of the environment.
[control]
# These hostname must be resolvable from your deployment host
192.168.201.2
#192.168.201.3
#192.168.201.4

# The above can also be specified as follows:
#control[01:03] ansible_ssh_user=kolla

# The network nodes are where your l3-agent and loadbalancers will run
# This can be the same as a host in the control group
[network]
192.168.201.2
#192.168.201.3
#192.168.201.4

[compute]
192.168.201.2
#192.168.201.3
#192.168.201.4

...
...
======================================================================

2 - Change it in /etc/kolla/globals.yml

kolla_internal_vip_address: "192.168.201.2"
enable_haproxy: "no"

3 - Run the prechecks: # ./tools/kolla-ansible prechecks -i inventory

The error logs generated

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
TASK: [prechecks | Checking if kolla_internal_vip_address and kolla_external_vip_address are not pingable from any node] ***
failed: [192.168.201.2] => (item=192.168.201.2) => {"changed": false, "cmd": ["ping", "-c", "3", "192.168.201.2"], "delta": "0:00:02.020890", "end": "2016-04-15 15:19:30.756474", "failed": true, "failed_when_result": true, "item": "192.168.201.2", "rc": 0, "start": "2016-04-15 15:19:28.735584", "stdout_lines": ["PING 192.168.201.2 (192.168.201.2) 56(84) bytes of data.", "64 bytes from 192.168.201.2: icmp_seq=1 ttl=64 time=16.0 ms", "64 bytes from 192.168.201.2: icmp_seq=2 ttl=64 time=0.188 ms", "64 bytes from 192.168.201.2: icmp_seq=3 ttl=64 time=0.095 ms", "", "--- 192.168.201.2 ping statistics ---", "3 packets transmitted, 3 received, 0% packet loss, time 2001ms", "rtt min/avg/max/mdev = 0.095/5.428/16.002/7.477 ms"], "warnings": []}
stdout: PING 192.168.201.2 (192.168.201.2) 56(84) bytes of data.
64 bytes from 192.168.201.2: icmp_seq=1 ttl=64 time=16.0 ms
64 bytes from 192.168.201.2: icmp_seq=2 ttl=64 time=0.188 ms
64 bytes from 192.168.201.2: icmp_seq=3 ttl=64 time=0.095 ms

--- 192.168.201.2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2001ms
rtt min/avg/max/mdev = 0.095/5.428/16.002/7.477 ms
failed: [192.168.201.2] => (item=192.168.201.2) => {"changed": false, "cmd": ["ping", "-c", "3", "192.168.201.2"], "delta": "0:00:02.002006", "end": "2016-04-15 15:19:32.880008", "failed": true, "failed_when_result": true, "item": "192.168.201.2", "rc": 0, "start": "2016-04-15 15:19:30.878002", "stdout_lines": ["PING 192.168.201.2 (192.168.201.2) 56(84) bytes of data.", "64 bytes from 192.168.201.2: icmp_seq=1 ttl=64 time=0.049 ms", "64 bytes from 192.168.201.2: icmp_seq=2 ttl=64 time=0.104 ms", "64 bytes from 192.168.201.2: icmp_seq=3 ttl=64 time=0.055 ms", "", "--- 192.168.201.2 ping statistics ---", "3 packets transmitted, 3 received, 0% packet loss, time 1998ms", "rtt min/avg/max/mdev = 0.049/0.069/0.104/0.025 ms"], "warnings": []}
stdout: PING 192.168.201.2 (192.168.201.2) 56(84) bytes of data.
64 bytes from 192.168.201.2: icmp_seq=1 ttl=64 time=0.049 ms
64 bytes from 192.168.201.2: icmp_seq=2 ttl=64 time=0.104 ms
64 bytes from 192.168.201.2: icmp_seq=3 ttl=64 time=0.055 ms

--- 192.168.201.2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1998ms
rtt min/avg/max/mdev = 0.049/0.069/0.104/0.025 ms

FATAL: all hosts have already failed -- aborting

PLAY RECAP ********************************************************************
           to retry, use: --limit @/root/prechecks.retry

192.168.201.2 : ok=52 changed=0 unreachable=0 failed=1