[testlib] Drop override of assertItemsEqual method
The override is not compatible with underlying (standard) method because it
builds sets and rely on eid.
Closes #3641111.
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))