Fix index error due to missing previously selected shapes in current image

Author: Ynjxsjmh

labelme/widgets/canvas.py

@@ -988,7 +988,11 @@ def keyReleaseEvent(self, ev):
             if int(modifiers) == 0:
                 self.snapping = True
         elif self.editing():
-            if self.movingShape and self.selectedShapes:
+            if (
+                self.movingShape
+                and self.selectedShapes
+                and self.selectedShapes[0] in self.shapes
+            ):
                 index = self.shapes.index(self.selectedShapes[0])
                 if self.shapesBackups[-1][index].points != self.shapes[index].points:
                     self.storeShapes()