[#4031] Remove _guess_group_type methods from org controller

It had "organization" hardcoded so it prevented custom organization
types to work properly. The parent implementation in the group
controller should work fine for orgs as well as it just uses the URL.

ckan/controllers/organization.py

@@ -20,9 +20,6 @@ class OrganizationController(group.GroupController):
 
     group_types = ['organization']
 
-    def _guess_group_type(self, expecting_name=False):
-        return 'organization'
-
     def _replace_group_org(self, string):
         ''' substitute organization for group if this is an org'''
         return re.sub('^group', 'organization', string)