remove overzealous escaping of reason in rebuild()

I'd like a second look at this, since these escapes were added while
resolving the XSS vulnerabilities back in 0.7.*.  I think they are
unnecessary, particularly with the use of Jinja.  I suspect they were
added out of an abundance of caution, lest the reason later be used
unescaped in a status display.

buildbot/status/web/build.py

@@ -170,7 +170,7 @@ def rebuild(self, req):
         name = req.args.get("username", ["<unknown>"])[0]
         comments = req.args.get("comments", ["<no reason specified>"])[0]
         reason = ("The web-page 'rebuild' button was pressed by "
-                  "'%s': %s\n" % (html.escape(name), html.escape(comments)))
+                  "'%s': %s\n" % (name, comments))
         extraProperties = getAndCheckProperties(req)
         if not bc or not b.isFinished() or extraProperties is None:
             log.msg("could not rebuild: bc=%s, isFinished=%s"