protocol: reject DLCX/CRCX/MDCX on unsupported parameters

When an unsupported MGCP parameter (e.g. N) is used, then this
parameter is ignored and the command execution continues. However,
an MGCP command that contains an unsupported parameter should
be rejected.

- Make sure that MGCP commands DLCX, CRCX and MDCX are rejected,
  when they contain unsupported parameters.

Change-Id: I8cd5987fc6befcd53a7c4916f77b1a24c904ba48
1 file changed