[FIX] ir_attachment: _filestore cache ignore uid

replace ormcache_context by ormcache: use the context in the cache key is useless
set skiparg=3 (default skiparg=2) so the uid is not used in the cache key: the filestore path is the same for all database users

openerp/addons/base/ir/ir_attachment.py

@@ -69,7 +69,7 @@ class ir_attachment(osv.osv):
     def _storage(self, cr, uid, context=None):
         return self.pool['ir.config_parameter'].get_param(cr, SUPERUSER_ID, 'ir_attachment.location', 'file')
 
-    @tools.ormcache_context()
+    @tools.ormcache(skiparg=3)
     def _filestore(self, cr, uid, context=None):
         return tools.config.filestore(cr.dbname)