Never downgrade ProtocolLib after an update. 

Also ensure the version number is incremented after an update.
Better to fail updating the version number than crashing.

If we update the number, we have to also use the "empty file" trick
to remove the old file, which will crash ProtocolLib on the first 
reload. It takes a second reload for it to function at all.

It's much better to take the hit on the version number, and avoid 
this issue altogether. The update method simply wasn't designed for 
plugins with version numbers in their file name.
Release of 3.3.1