post_init must be called on the database

.. otherwise things set up in post_init (notably rev_multilink
properties) will be missing. Note that post_init is idempotent and can
be called multiple times.

Author: schlatterbeck

roundup/instance.py

@@ -133,6 +133,8 @@ def open(self, name=None):
                 extension(self)
             detectors = self.get_extensions('detectors')
         db = env['db']
+        # *Must* call post_init! It is not an error if called multiple times.
+        db.post_init ()
         db.tx_Source = None
 
         # apply the detectors