mgcp_conn_get(): match conn Id ('I:') despite leading zeros

The Connection Identifier is defined as a hex string, so clients may send the
ID back with or without leading zeros. Ignore all leading zeros when comparing.

A specific SCCPlite MSC is observed to DLCX with Connection Identifier with
leading zeros removed, which would mismatch pefore this patch.

Extend test_conn_id_matching() in mgcp_test.c to include leading zero tests.

Now, mgcp_conn_get() would match a valid id with *any* amount of leading zeros,
even if that far surpasses the permitted conn id length. Valid lengths of
incoming conn ids should be and is checked elsewhere.

Related: OS#3509
Change-Id: If55a64a2da47b6eff035711c08e4114d70dbec91
3 files changed