ttcn3-asterisk: Allow running testsuite with IPv4 and IPv6 configs
Requires [1] to be able to run SIPmsg_PT in Asterisk_Tests with IPv6
support.
[1] https://gitlab.eclipse.org/eclipse/titan/titan.TestPorts.SIPmsg/-/merge_requests/4
Related: SYS#6982
Change-Id: I1de922c681fef4d308898cd592544aef25901c7b
