MGCP_Test: Relax expected number of packets in TC_one_crcx_receive_only_rtp

The testcase TC_one_crcx_receive_only_rtp performs a short RTP
transmission that lasts about 1 second. Then it conuts out the number of
packets that are transmitted and checks against a fixed value. The
compare values are determined using experimentation and reflect the
number of bytes/packets that one could expect under normal conditions on
an average machine.

However, there may be load sitations on the test host that may cause that
a too little number of packets is transmitted and the test will fail. Lets
reduce the number a bit as the only thing we want to make sure with this
is that there are at least some (more than one or two) packets transmitted

Change-Id: Ie63445d61268d178940ce8d9cfa984519c42041a
1 file changed