log: don't spam with "can not patch PT" messages

currently, when looking at an osmo-mgw log output with a phone call working
completely fine, you see these messages on LOGL_ERROR for each RTP packet:

20190304221420619 DRTP ERROR endpoint:0x0 can not patch PT because no suitable egress codec was found. (mgcp_network.c:761)
20190304221420639 DRTP ERROR endpoint:0x1 can not patch PT because no suitable egress codec was found. (mgcp_network.c:761)
20190304221420639 DRTP ERROR endpoint:0x0 can not patch PT because no suitable egress codec was found. (mgcp_network.c:761)
20190304221420659 DRTP ERROR endpoint:0x1 can not patch PT because no suitable egress codec was found. (mgcp_network.c:761)
20190304221420659 DRTP ERROR endpoint:0x0 can not patch PT because no suitable egress codec was found. (mgcp_network.c:761)

Put these messages on DEBUG level instead. They currently do not convey useful
information.

Possibly our MGCP clients could use some changes in behavior regarding payload
types, but since that topic is quite unresolved, let's not spam the ERROR log
level with this.

Change-Id: I4afc41fd472ec8ba887b9263fbac62de50d7cef9
1 file changed