Fix for shift handling in chatbox
Fix for shift handling in chatbox

I used pull request #11 as the base for @9b976cf9b8, but I forgot
to fix this aspect of it.

QuiteQuiet/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,submindraikou/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,panpawn/Gold-Client,panpawn/Gold-Client,submindraikou/Pokemon-Showdown-Client,panpawn/Gold-Client,QuiteQuiet/Pokemon-Showdown-Client,sirDonovan/Pokemon-Showdown-Client,QuiteQuiet/Pokemon-Showdown-Client,Zarel/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client,asgdf/Pokemon-Showdown-Client