Fix dangling pointers causing erratic timer behaviour (affects taskbar with spacing); use calloc instead of malloc for safer initializations

git-svn-id: http://tint2.googlecode.com/svn/trunk@758 121b4492-b84c-0410-8b4c-0d4edfb3f3cc

src/taskbar/taskbar.c

@@ -109,7 +109,6 @@ void cleanup_taskbar()
 	urgent_list = NULL;
 
 	stop_timeout(urgent_timeout);
-	urgent_timeout = NULL;
 }