Don't Fuck With Paste v2.7 
This add-on stops websites from blocking copy and paste actions for password fields and other input fields.
Test page available here, try before downloading the add-on then installing the add-on, activate it, and try again: https://jsfiddle.net/aaronraimist/6qrnwcjp/28/show
Source code available here: https://github.com/aaronraimist/DontFuckWithPaste
This add-on was originally created by Jacob Swanner for Chrome is now available in Firefox. Please don't ask Jacob for support with the Firefox version of the add-on.