web: select password field contents on focus

[wjt]

I'm running a Vault of my very own on https://v.wjt.me.uk/ and took the chance to fix a papercut that bothers me every time I use it.

It's no help on Android – the text is selected but the edit bar doesn't come up so it can't be copied – but it seems to work fine on desktop.

[mriehl]

+1 works great for me, thanks a lot!

[jcoglan]

Thanks @wjt!