Fix a use after free in a 'theoretical' case in switch_cache_db_persistant_execute_trans_full where the pre_trans_execute statement fails, but SQLSetAutoCommitAttr succeeds

we always have the caller profile at this point, if for some reason we don't just instead of crashing

Correction to commit 0ba59aa6 using the correct variable in tel uri param parsing for mod_sofia

add heartbeat_use_scheduler variable to force the heartbeat to use the scheduler rather than the media stream and also make it auto-chage between modes when going in and out of the media path