[R5.0-50]- IPv6- agent crash when Fat flow is configured with ignore address

Agent keep crashing when Fat flow is configured with ignore address for IPv6 and also hold flow is seen when agent comes up.

traffic is ssh session from 1::3 to 2::3, both VM's are on same node nodec62.

destination VMI:

vif0/3 OS: tap4dc74aa1-55
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:0.0.0.0
            IP6addr:2::3
            Vrf:5 Mcast Vrf:5 Flags:PL3L2DEr QOS:-1 Ref:6
            RX packets:164 bytes:23074 errors:0
            TX packets:167 bytes:50710 errors:0
            Drops:1
            FatFlows (Protocol/Port): 6:* - Dip

source VMI:

vif0/6 OS: tap6385a3df-43
            Type:Virtual HWaddr:00:00:5e:00:01:00 IPaddr:0.0.0.0
            IP6addr:1::3
            Vrf:4 Mcast Vrf:4 Flags:PL3L2DEr QOS:-1 Ref:6
            RX packets:156 bytes:22326 errors:0
            TX packets:159 bytes:48420 errors:0
            Drops:1

    Index Source:Port/Destination:Port Proto(V)
-----------------------------------------------------------------------------------
    18780 2::3:0 6 (5)
                         :::0
(Gen: 4, K(nh):34, Action:H, Flags:, TCP:, QOS:0, S(nh):0, Stats:2/188,
 SPort 0, TTL 0, Sinfo 3.0.0.0)

   344720<=>474728 1::3:53340 6 (4)
                         2::3:22
(Gen: 2, K(nh):29, Action:F, Flags:, TCP:S, QOS:-1, S(nh):29, Stats:1/94,
 SPort 50911, TTL 0, Sinfo 6.0.0.0)

   474728<=>344720 2::3:22 6 (5)
                         1::3:53340
(Gen: 2, K(nh):34, Action:F, Flags:, TCP:Sr, QOS:-1, S(nh):34, Stats:0/0,

(gdb) bt
#0 0x00007ff7b0f8b1f7 in raise () from /lib64/libc.so.6
#1 0x00007ff7b0f8c8e8 in abort () from /lib64/libc.so.6
#2 0x00007ff7b0f84266 in __assert_fail_base () from /lib64/libc.so.6
#3 0x00007ff7b0f84312 in __assert_fail () from /lib64/libc.so.6
#4 0x0000000002112666 in TaskImpl::execute (this=0x7ff7ab3f7c40) at src/contrail-common/base/task.cc:310
#5 0x00007ff7b1b5a8ca in ?? ()
#6 0x0101000000000015 in ?? ()
#7 0x00007ff7ab3c7f40 in ?? ()
#8 0x0000000000000001 in ?? ()
#9 0x00007ff7a9e27c88 in ?? ()
#10 0x00007ff7ab3c7f28 in ?? ()
#11 0x0000000000000000 in ?? ()

Note: this is private agent binary with fix for bug 1761157.

[root@nodec62 ~]# ls -l /var/crashes/| wc -l
39