mgcp-client: Transmit remote IP addr in CRCX if known and port=0

A client may know the IP address during CRCX but not yet the port, or it
may simply want to hint an initial IP address so that the MGW can better
guess when allocating a local IP address.

Related: SYS#6657
Change-Id: I30165dbac5e484011d0acf46af36f105954a501d
2 files changed