filemerge: only run test for issue3581 on non-windows environments stable

filemerge: only run test for issue3581 on non-windows environments

--- a/tests/test-merge-tools.t	Thu Nov 01 13:46:03 2012 +0100
+++ b/tests/test-merge-tools.t	Tue Oct 30 17:23:51 2012 -0700
@@ -775,6 +775,7 @@
 
 Issue3581: Merging a filename that needs to be quoted
 
+#if no-windows
   $ beforemerge
   [merge-tools]
   false.whatever=
@@ -796,6 +797,7 @@
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg update -C 1 > /dev/null
+#endif
 
 Merge post-processing