279 disconnect connect fix
Created by: ThomasArts
This fixes the problem and does not introduce more problems.
Note that send_cache is only used in module roster_presence (it actually should be moved there inmy opinion).
Whatever it returns is ignored. If it fails it fails in the same way as any other crash (see try-catch around it) and would simply have a weird return error on on_connect. That function is always used in a catch and the return valueis ignored.