[#4801] Use Webob Request.queryvars in friendly form plugin

Request.params exists in webob 1.0.8 but itchanges the wsgi
environ and makes submitted form params not available later on.
This will probably affect py3 as well but we are not yet at a stage
where it can be tested, so we'll need to revisit it.

ckan/lib/repoze_plugins/friendly_form.py

@@ -291,11 +291,11 @@ def _get_logins(self, environ, force_typecast=False):
 
         '''
         try:
-            # Webob 1.8.5 (py3)
-            variables = Request(environ).params
-        except AttributeError:
             # Webob 1.0.8 (py2)
             variables = Request(environ).queryvars
+        except AttributeError:
+            # Webob 1.8.5 (py3)
+            variables = Request(environ).params
 
         failed_logins = variables.get(self.login_counter_name)
         if force_typecast: