Remove not needed nesting for resize (#460)

src/index.tsx

@@ -856,7 +856,7 @@ export class App extends React.Component<{}, AppState> {
                   const { x, y } = viewportCoordsToSceneCoords(e, this.state);
                   let deltaX = 0;
                   let deltaY = 0;
-                  selectedElements.forEach(element => {
+                  const element = selectedElements[0];
                   switch (resizeHandle) {
                     case "nw":
                       deltaX = lastX - x;
@@ -924,7 +924,7 @@ export class App extends React.Component<{}, AppState> {
                   el.x = element.x;
                   el.y = element.y;
                   el.shape = null;
-                  });
+
                   lastX = x;
                   lastY = y;
                   // We don't want to save history when resizing an element