extdiff: do not shell-quote options to new commands
revert a change introduced by 453097750fbf
--- a/hgext/extdiff.py
+++ b/hgext/extdiff.py
@@ -105,8 +105,7 @@ def dodiff(ui, repo, diffcmd, diffopts,
else:
dir2 = snapshot_wdir(modified + added)
cmdline = ('%s %s %s %s' %
- (util.shellquote(diffcmd),
- ' '.join(map(util.shellquote, diffopts)),
+ (util.shellquote(diffcmd), ' '.join(diffopts),
util.shellquote(dir1), util.shellquote(dir2)))
ui.debug('running %r in %s\n' % (cmdline, tmproot))
util.system(cmdline, cwd=tmproot)