EDIT: It seems Facebook have corrected the issue on their side.
You should be safe to re-install original telepathy-gabble:

From the work done on N9, to solve Facebook connection/contacts issue, I have patched the telepathy-gabble library to be able to once again use Facebook chat.
The version number is NOT changed - this is to avoid issues that would create dependencies problems when trying to use apt-get to install remove programs.

Original thread from N9 which solved this issue: http://talk.maemo.org/showthread.php?t=91187

And, patched deb which can be installed using dpkg -i telepathy-gabble_0.8.13-0maemo3+0m5_armel.deb as root user

Shared on 4shared, as it is too big to attach here.

http://www.4shared.com/file/TtmDKDBF...-0maemo30.html

Dropbox link
https://dl.dropboxusercontent.com/u/...B0m5_armel.deb