Resolves: tdf#106732 the intent was surely to return a const ref

Change-Id: Iaaa1f76a689645adaebf4fe5b87003ad238f71f2

include/svtools/insdlg.hxx

@@ -60,7 +60,7 @@ public:
                                 return aObjectServerList.size();
                             }
 
-    const SvObjectServer    operator[]( size_t n ) const
+    const SvObjectServer&   operator[]( size_t n ) const
                             {
                                 return aObjectServerList[ n ];
                             }