use explicitly stageImage() after an immage has been dragged and dropped into the text input field

deltachat-ios/Chat/ChatViewController.swift

@@ -2410,7 +2410,7 @@ extension ChatViewController: ChatInputTextViewPasteDelegate {
         sendSticker(image)
     }
     func onImageDragAndDropped(image: UIImage) {
-        onImageSelected(image: image)
+        stageImage(image)
     }
 }