Upgrade to jquery 3.3.1

[Richard-NL]

No description provided.

[peterwake]

Note that this update causes a glitch with the custom scrollbar plugin https://github.com/malihu/malihu-custom-scrollbar-plugin. This uses$(window).load(function(){ which has been deprecated, and now needs to be $(window).on("load", function(){

Unfortunately looks like now looks like the custom scrollbar repo isn't maintained. You need to update per this forked commit:

https://github.com/cowcross/RichFilemanager/commit/d9ae82235b1b1b9306e3f579e1dd3cd1ffc28b0c

[psolom]

now needs to be $(window).on("load", function(){})

Does custom-scrollbar-plugin work correct with this fix?

You need to update per this forked commit

Could you include required fixed for custom-scrollbar-plugin into this PR to provide a complete solution?