[PATCH] gitk: Continue and show error message in new repos

If there is no commit made yet, gitk just dumps a Tcl error on stderr,
which sometimes is hard to see.  Noticed when gitk was run from Xfce
file manager (thunar's custom action).

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -427,7 +427,7 @@ proc readrefs {} {
 	    lappend idotherrefs($id) $name
 	}
     }
-    close $refd
+    catch {close $refd}
     set mainhead {}
     set mainheadid {}
     catch {