reverted patch 58ecc0e2e6fc as it may hide an other issue

frontends/src/quick_frontend/quick_contact_list.py

@@ -390,10 +390,7 @@ class QuickContactList(QuickWidget):
         except KeyError:
             log.warning(_(u"Trying to delete an unknow entity [{}]").format(entity))
         if in_roster:
-            try:
-                self._roster.remove(entity_bare)
-            except KeyError:
-                pass  # contact has been removed already from a concurrent client?
+            self._roster.remove(entity_bare)
         del self._cache[entity_bare]
         for group in groups:
             self._groups[group]['jids'].remove(entity_bare)