svn: fix usage of http exception from webob to pyramid one.

Webob exception had an condition that was unfilled for svn causing unexpected 500s.

rhodecode/lib/middleware/simplesvn.py

@@ -24,7 +24,7 b' import urllib'
 from urlparse import urljoin
 
 import requests
-from webob.exc import HTTPNotAcceptable
+from pyramid.httpexceptions import HTTPNotAcceptable
 
 from rhodecode.lib import caches
 from rhodecode.lib.middleware import simplevcs