fix release build (typo causing build failure)

src/AvaloniaEdit/Rendering/CollapsedLineSection.cs

@@ -35,7 +35,7 @@ namespace AvaloniaEdit.Rendering
 		internal string Id;
 	    private static int _nextId;
 		#else
-		internal const string ID = "";
+		internal const string Id = "";
 		#endif
 		
 		internal CollapsedLineSection(HeightTree heightTree, DocumentLine start, DocumentLine end)