Modified JS to allow for default click event to occur if the submenu of ...

I Modified the JS to allow for default click event to occur if the submenu of the Redux admin_menu is not a Redux settings panel. This allows for add_sub_menu to be used under the Redux main menu.

My use case is as follows: 

For a plugin I'm working on, I want the top-level Admin Menu to be the Redux Settings panel, and I want several CPTs (and possibly other items, such as custom taxonomies) to be sub-menus under that top-level Admin Menu created by Redux. 

When adding anything as a sub-menu to the Redux Menu, the JS prevents the default click event, meaning CPTs, etc cannot be a sub-menu to a Redux Admin Menu. The change I've submitted allows for the Redux Submenus to still work AND allows other custom sub-menu items to be added as well, as it now checks to see if the submenu is a _section_group_li_a before it prevents the default click action.