Added better line-height

@see http://beta.woltlab.com/index.php/Thread/2248-CodeMirror-mehr-line-height/
Reverted fa20fa9b0c
Added better line-height

@see http://beta.woltlab.com/index.php/Thread/2248-CodeMirror-mehr-line-height/
Merge pull request #1575 from KittBlog/codeMirror-line-height

Added better line-height