Cannot .enable_fts() for columns with spaces in their names

[simonw]

import sqlite_utils
db = sqlite_utils.Database(memory=True)                                 
db["test"].insert({"space in name": "hello"})                           
db["test"].enable_fts(["space in name"])                                
---------------------------------------------------------------------------
OperationalError                          Traceback (most recent call last)
<ipython-input-8-ce4b87dd1c7a> in <module>
----> 1 db['test'].enable_fts(["space in name"])

/usr/local/lib/python3.7/site-packages/sqlite_utils/db.py in enable_fts(self, columns, fts_version, create_triggers)
    755         )
    756         self.db.conn.executescript(sql)
--> 757         self.populate_fts(columns)
    758 
    759         if create_triggers:

/usr/local/lib/python3.7/site-packages/sqlite_utils/db.py in populate_fts(self, columns)
    787             table=self.name, columns=", ".join(columns)
    788         )
--> 789         self.db.conn.executescript(sql)
    790         return self
    791 

OperationalError: near "in": syntax error