[sqlite] Fix integrity error parsing
Up to sqlite 3.7, integrity error message may be in the singular form
if only one column is in the unique index.
Closes #5224632
import ConfigParser
try:
undo_actions = config.cfgfile_parser.get('MAIN', 'undo-support', False)
except ConfigParser.NoOptionError:
pass # this conf. file was probably already migrated
else:
config.global_set_option('undo-enabled', bool(undo_actions))