Fix Add Comment input height to match submit button (#1823)
Fix Add Comment input height to match submit button (#1823)

Add Comment input box in the Comments tab is smaller than the submit button.
We don't have that problem in translation comments, because line-height is
defined in History.css.
mozilla/pontoon,mathjazz/pontoon,mathjazz/pontoon,mozilla/pontoon,mathjazz/pontoon,mozilla/pontoon,mozilla/pontoon,mathjazz/pontoon,mozilla/pontoon,mathjazz/pontoon