skip element mutation on noop updates (#1667)

src/tests/__snapshots__/move.test.tsx.snap

@@ -40,8 +40,8 @@ Object {
   "strokeStyle": "solid",
   "strokeWidth": 1,
   "type": "rectangle",
-  "version": 5,
-  "versionNonce": 1116226695,
+  "version": 4,
+  "versionNonce": 1150084233,
   "width": 30,
   "x": -10,
   "y": 60,

src/tests/move.test.tsx

@@ -83,7 +83,7 @@ describe("duplicate element on move when ALT is clicked", () => {
     fireEvent.pointerMove(canvas, { clientX: 10, clientY: 60 });
     fireEvent.pointerUp(canvas);
 
-    expect(renderScene).toHaveBeenCalledTimes(5);
+    expect(renderScene).toHaveBeenCalledTimes(4);
     expect(h.state.selectionElement).toBeNull();
     expect(h.elements.length).toEqual(2);