[web] Stop patching jquery.treeview.js This logically reverts part of e9b7cd2e9012 "allow treeview to work correctly in a tab #345293". The treeview and ajax code have suffered a number of changes since then, this change doesn't seem to be necessary anymore. It is most likely unneeded since f65208c9dbdc "[javascript] use jQuery.one('ajax-loaded') instead of jQuery.bind() in add_onload to avoid multiple callback executions".

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))