Allow the message dialog to grow higher.

Kitty, Jetryl and zookeeper aren't too fond of the scrollbars in the
dialog if the text gets too long. Technically it's the easiest solution
to make things working in all cases. So we decided to let the dialog to
grow near the top so the scrollbars will pop up less frequently and
hopefully never.

changelog

@@ -9,6 +9,8 @@ Version 1.5.7+svn:
      dialog (the effect is percieved as the new dialog not showing up).
    * Spacebar closes the dialogs without a scrollbar again.
    * Pressing escape in a new dialog, behaves like in the old dialogs again.
+   * The new portrait dialogs can get higher so the scrollbars are less often
+     visible.
  * Language and i18n:
    * updated translations: German, Hungarian, Italian, Japanese, Slovak,
      Spanish

data/gui/default/window/message.cfg

@@ -321,9 +321,9 @@
 		automatic_placement = "false"
 
 		x = 0
-		y = "(screen_height - " + {_GUI_IMAGE_WIDTH} + ")"
+		y = 30
 		width = "(screen_width - 142)"
-		height = {_GUI_IMAGE_WIDTH}
+		height = "(screen_height - 30)"
 
 		easy_close = "true"