text-channel: rename static vars/function to match the feature name
text-channel: rename static vars/function to match the feature name

The actual name of the feature is INCOMING_MESSAGE, not PENDING_MESSAGE.

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib