Remove confusing delete from wxIdRangeManager dtor.

The singleton dtor shouldn't delete the global singleton object, if this were
ever really possible, it would result in an infinite recursion. And even
though it was not (because ms_instance was reset to NULL before destroying the
object pointed by it), this delete was still confusing and unnecessary, so
remove it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75988 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/xrc/xmlres.cpp

@@ -1262,8 +1262,6 @@ wxIdRangeManager::~wxIdRangeManager()
         delete *i;
     }
     m_IdRanges.clear();
-
-    delete ms_instance;
 }
 
 void wxIdRangeManager::AddRange(const wxXmlNode* node)