Get rid of the HMxcImage undefined py warnings

src/gui/Base/HMxcImage.qml

@@ -23,6 +23,8 @@ HImage {
 
 
     function update() {
+        if (! py) return  // component was destroyed
+
         let w = sourceSize.width || width
         let h = sourceSize.height || height
 
@@ -31,8 +33,6 @@ HImage {
             return
         }
 
-        if (! image) return  // if it was destroyed
-
         if (! isMxc) {
             if (source !== mxc) source = mxc
             show = image.visible