Drop GetEnumerator() method in CodeElements interface to fix warning

src/AddIns/Misc/PackageManagement/SharpDevelop.EnvDTE/Src/CodeElements.vb

@@ -23,7 +23,5 @@ Namespace EnvDTE
 		ReadOnly Property Count() As Integer
 		
 		Function Item(index As Object) As CodeElement
-		
-		Function GetEnumerator() As IEnumerator
 	End Interface
 End Namespace