don't change the value of the hash element if insert() didn't add it (closes #10261)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@57388 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/hashmap.h

@@ -660,8 +660,6 @@ public: \
         Node *node = GetOrCreateNode( \
                 CLASSNAME##_wxImplementation_Pair( v.first, v.second ), \
                 created); \
-        if ( !created ) \
-            node->m_value.second = v.second; \
         return Insert_Result(iterator(node, this), created); \
     } \
  \