fix metatype declaration in a few places

Change-Id: I76a12a278db8e74d935e76a5e832daf8e34df2a9
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/help/helpindexfilter.cpp

@@ -50,8 +50,6 @@ using namespace Core;
 using namespace Help;
 using namespace Help::Internal;
 
-Q_DECLARE_METATYPE(ILocatorFilter*)
-
 HelpIndexFilter::HelpIndexFilter()
     : m_needsUpdate(true)
 {