#85 unfocus keyboard on sending text disabled

Now the keyboards is always visible when we click on say button (#85).
I use this to prevent that behaviour: 
https://github.com/mozilla-b2g/gaia/blob/1e66ee35c4fb1aa46c615241d91711e6121662b9/apps/sms/js/sms.js#L820

its tricky, but works :tongue: