Prevent scale/size change invisible WebView

app/src/main/java/eu/faircode/email/WebViewEx.java

@@ -196,6 +196,7 @@ public class WebViewEx extends WebView implements DownloadListener, View.OnLongC
             @Override
             public void onScaleChanged(WebView view, float oldScale, float newScale) {
                 Log.i("Changed scale=" + newScale);
+                if (getVisibility() == View.VISIBLE)
                     intf.onScaleChanged(newScale);
             }
 
@@ -290,6 +291,7 @@ public class WebViewEx extends WebView implements DownloadListener, View.OnLongC
     protected void onSizeChanged(int w, int h, int ow, int oh) {
         super.onSizeChanged(w, h, ow, oh);
         Log.i("Size changed height=" + h);
+        if (getVisibility() == View.VISIBLE)
             this.intf.onSizeChanged(w, h, ow, oh);
     }