[SCHEMA CHANGE] Cleanup *_user_text in DB

When we moved *_user_text stuff to *_user_ip, we never actually
got rid of *_user_text columns in the DB.
These columns still exist, though they shouldn't. Especially
flow_workflow.workflow_user_text, which is NOT NULL, but is now
always fed null values.
It seems that production etc. is tolerant and still lets our
inserts in, but we should definitely get rid of those columns.

Change-Id: I03fefcda5cdd360404b7912fb0008f5a71f8250e
Merge "[SCHEMA CHANGE] Cleanup *_user_text in DB"