More robust workaround for EFTYPE only being present on BSD

git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup@847 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

trunk/rdiff-backup/rdiff_backup/rpath.py

@@ -832,8 +832,8 @@ class RPath(RORPath):
 		try:
 			self.conn.os.chmod(self.path, permissions & Globals.permission_mask)
 		except OSError, e:
-		    # XXX: BSD defines EFTYPE as 79, but it is not in python
-			if e.errno == 79 and not self.isdir():
+			if e.strerror == "Inappropriate file type or format" \
+					and not self.isdir():
 				# Some systems throw this error if try to set sticky bit
 				# on a non-directory. Remove sticky bit and try again.
 				log.Log("Unable to set permissions of %s to %o - trying again"