asterisk: dnsmasq.conf: Avoid forwarding queries to other DNS servers
This creates problems when requesting resolution of the IPv6 address. For some reason, dnsmasq was forwarding the request to the non-available google DNS servers, and Asterisk docker container pre-start commands checking for DNS resolution would never pass when run in jenkins node.
asterisk: Wait for Asterisk ready before starting testsuite
A recent commit made Asterisk wait for dnsmasq to be ready before starting it. This means Asterisk takes more time now to be ready itself, hence we need to delay launching the testsuite until it is ready. Otherwise, the entire set of tests may be run even before Asterisk gets to answer on the AMI socket.
