Handle presence received before roster

Presence of contact not found in roster are filtered out.
But sometimes roster is received after a first few presences.

We choose to store presences until we receive roster and then process
this presences.

Fixes #1050

src/event/server_events.c

@@ -115,6 +115,7 @@ sv_ev_roster_received(void)
         ui_show_roster();
     }
 
+    roster_process_pending_presence();
     char *account_name = session_get_account_name();
 
 #ifdef HAVE_LIBGPGME