Postgres migration script broken on groups

[turt2live]

Description

2017-11-13 14:55:19,980 - synapse.metrics - 162 - INFO - Collecting gc 0
Traceback (most recent call last):
  File "/home/travis/.synapse/bin/synapse_port_db", line 541, in run
    consumeErrors=True,
FirstError: FirstError[#24, [Failure instance: Traceback: <class 'psycopg2.ProgrammingError'>: column "is_admin" is of type boolean but expression is of type integer
LINE 1: ...LUES ('+testing:dev.t2bot.io', '@travis:dev.t2bot.io', 1, 1)
                                                                  ^
HINT:  You will need to rewrite or cast the expression.

Version information

• Homeserver: dev.t2bot.io
• Version: develop as of reporting
• Install method: pip
• Platform: Ubuntu 16.04 VM