activity_history table has incorrectly defined PRIMARY KEY

The PRIMARY KEY schema definition for the activity_history table was defined wrong.

The PRIMARY KEY here is a two field key of uid and aid. The schema definition should have been array('uid', 'aid') but was defined as array('uid, aid').

In actuality despite the incorrect syntax the key was still correctly defined in PostgreSQL (and would appear to have been OK in MySQL as the db_add_primary_key function as written would work with the bad string. I discovered the problem after running the schema module against the installed tables.

Fixed in CVS.