conversationmodel: sort conversations in clearAllHistory

Gitlab: #411
Change-Id: I8622d5e23a4b99530cfc98ec4ef76b7e05a7f543
Reviewed-by: Sébastien Blin <sebastien.blin@savoirfairelinux.com>

src/conversationmodel.cpp

@@ -915,6 +915,8 @@ ConversationModel::clearAllHistory()
         }
         database::getHistory(pimpl_->db, conversation);
     }
+    pimpl_->sortConversations();
+    emit modelSorted();
 }
 
 void