This fixes a couple of issues with celtclient.c and makes it easier to change the channel count and deactivate the AEC.
This fixes a couple of issues with celtclient.c and makes it easier to
change the channel count and deactivate the AEC.

oneman/opus-oneman,oneman/opus-oneman,Distrotech/celt,oneman/opus-oneman,Distrotech/celt,mumble-voip/celt-0.11.0,mumble-voip/celt-0.11.0,dezelin/celt,dezelin/celt,mumble-voip/celt-0.11.0,dezelin/celt,mumble-voip/celt-0.7.0,Distrotech/celt,mumble-voip/celt-0.7.0,mumble-voip/celt-0.7.0