db: Fix memleaks

src/database.c

@@ -315,6 +315,7 @@ log_database_get_previous_chat(const gchar *const contact_barejid)
         history = g_slist_append(history, msg);
 	}
 	sqlite3_finalize(stmt);
+    free(query);
 
     return history;
 }

src/ui/chatwin.c

@@ -491,8 +491,7 @@ _chatwin_history(ProfChatWin *chatwin, const char *const contact_barejid)
         }
         chatwin->history_shown = TRUE;
 
-        //TODO: message_free
-        g_slist_free_full(history, free);
+        g_slist_free_full(history, (GDestroyNotify)message_free);
     }
 }