[web/data] Add missing mode='swap' in loadxhtml calls (closes #5087432)
Let's avoid putting divs inside divs, dawg.
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))