blank vars in conf file can cause tests to choke

in the conf file canonical-certification.conf, there are a couple items that are empty:

#KVM_TIMEOUT =

And

#TEST_PASS =

The problem we're seeing is that testers uncomment these as necessary but forget to fill them in.

Scenario 1: Tester using local cloud image for virt testing, uncomments these lines:

#KVM_TIMEOUT =
#KVM_IMAGE =

But only fill in KVM_IMAGE. This can cause the virtualization test to choke as the env var KVM_TIMEOUT overrides the default in the script and can create issues.

Scenario 1: Tester donig iperf testing uncomments the four lines for network testing correctly but fails to fill in

#TEST_PASS =

with a generic fake password. The network script sees this is empty and still tries evaluating the var and can choke because it's left empty.

To be honest, this is not something I've encountered myself, but based on feedback. IN any case, the MR that changes these values in the config file is innocuous enough that it wont hurt anything.