Fix vertical spacing of Issue Title bar
Summary
Issue title bar contents should be centered vertically. Currently, they are 1-2 pixels lower than they should be.
Steps to reproduce
View any issue's title bar. Look at Close and New issue buttons.
Screen cap
![Issues_header](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)
Edited
by
Shane Bouchard