mod_http_muc_log: Drop support for pre-0.11 MUC API
The oldest supported Prosody branch is 0.11, therefore we can drop code
for the MUC API of Prosody 0.10 and before.
The module:shared("rooms") method was never even in a release...
This module helps reduces power usage of inactive mobile clients while
another client is actively used. E.g. in the case of chatting on a
desktop computer, instantly pushing messages to a phone in someones
pocket is not the best use of radio time.
Works with [mod_csi_simple][doc:modules:mod_csi_simple] which is
included with Prosody since 0.11