Changes

hnbgw: Use Misc_Helpers.f_shutdown upon rx of unexpected msg

Otherwise the test continues for a while and ends up with a DTE which
makes it harder to figure out the original test failure.

Change-Id: I7f07cff2ce93e8b11338ba4e39e1d49662323f58

MGCP_Emulation: Make sure peer is running before Tx

This avoid DTE with "Broken pipe" if messages are being transmitted
while tear down process has already started, even if components are
created as "alive".

Change-Id: I8724870b9b967ffa49c3da03e1cdb2941f81653a