[migration] Ignore IOError from readline.write_history_file (closes #2106621)
We already ignore them when reading the histfile, no reason writing it
back should be any different.
option_group_changed('port', 'main', 'web')
option_group_changed('query-log-file', 'main', 'web')
option_group_changed('profile', 'main', 'web')
option_group_changed('max-post-length', 'main', 'web')