Fix Categories

--- ./usr/share/applications/pencil.desktop
+++ ./usr/share/applications/pencil.desktop
@@ -8,6 +8,6 @@ Terminal=false
 Type=Application
 StartupNotify=true
 Icon=/usr/share/pencil/skin/classic/icon.svg
-Categories=Graphics;2DGraphics;Development;
+Categories=Development;GUIDesigner;
 MimeType=application/ep;