Help: Remove several unused icons

Change-Id: I3a8cc0413b728606d79aa36fa0fd45553f204e5a
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/help/help.qrc

@@ -1,17 +1,9 @@
 <RCC>
     <qresource prefix="/help">
-        <file>images/find.png</file>
-        <file>images/book.png</file>
         <file>images/category_help.png</file>
         <file>images/mode_help.png</file>
         <file>images/mode_help@2x.png</file>
         <file>images/mode_help_mask.png</file>
         <file>images/mode_help_mask@2x.png</file>
     </qresource>
-    <qresource prefix="/trolltech/assistant" >
-        <file>images/mac/addtab.png</file>
-        <file>images/mac/closetab.png</file>
-        <file>images/win/addtab.png</file>
-        <file>images/win/closetab.png</file>
-    </qresource>
 </RCC>