fix gross white bottom margin in devhub modals (bug 1027405)
fix gross white bottom margin in devhub modals (bug 1027405)

diox/zamboni,Jobava/zamboni,ayushagrawal288/zamboni,mudithkr/zamboni,ayushagrawal288/zamboni,luckylavish/zamboni,Jobava/zamboni,ingenioustechie/zamboni,mstriemer/zamboni,mozilla/zamboni,mudithkr/zamboni,ngokevin/zamboni,Hitechverma/zamboni,diox/zamboni,jasonthomas/zamboni,andymckay/zamboni,shahbaz17/zamboni,Jobava/zamboni,shahbaz17/zamboni,ingenioustechie/zamboni,jamesthechamp/zamboni,ngokevin/zamboni,mozilla/zamboni,jamesthechamp/zamboni,tsl143/zamboni,washort/zamboni,luckylavish/zamboni,jamesthechamp/zamboni,washort/zamboni,washort/zamboni,elysium001/zamboni,eviljeff/zamboni,Jobava/zamboni,clouserw/zamboni,Hitechverma/zamboni,clouserw/zamboni,ingenioustechie/zamboni,mudithkr/zamboni,mozilla/zamboni,tsl143/zamboni,Hitechverma/zamboni,mstriemer/zamboni,eviljeff/zamboni,ddurst/zamboni,jasonthomas/zamboni,diox/zamboni,ingenioustechie/zamboni,mozilla/zamboni,ddurst/zamboni,andymckay/zamboni,diox/zamboni,washort/zamboni,elysium001/zamboni,kumar303/zamboni,luckylavish/zamboni,shahbaz17/zamboni,ayushagrawal288/zamboni,elysium001/zamboni,ngokevin/zamboni,clouserw/zamboni,jasonthomas/zamboni,jamesthechamp/zamboni,andymckay/zamboni,shahbaz17/zamboni,eviljeff/zamboni,ddurst/zamboni,mudithkr/zamboni,elysium001/zamboni,kumar303/zamboni,mstriemer/zamboni,Hitechverma/zamboni,tsl143/zamboni,kumar303/zamboni,tsl143/zamboni,clouserw/zamboni,mstriemer/zamboni,kumar303/zamboni,ayushagrawal288/zamboni,jasonthomas/zamboni,luckylavish/zamboni,eviljeff/zamboni,ddurst/zamboni