Fix event handler for clicking on story text

It wouldn't trigger any events originally when you click on parts of the
story text area that didn't contain any text, e.g. on a blank line or on
the blank part of a line to the right of the actual text.

static/application.js

@@ -1352,7 +1352,7 @@ $(document).ready(function(){
 		chunkOnKeyDown
 	).on('paste', 
 		chunkOnPaste
-	).on('focus',
+	).on('click',
 		chunkOnSelectionChange
 	).on('keydown',
 		chunkOnSelectionChange