fixed overlapping images

deltachat-ios/MessageKit/Views/Cells/TextMediaMessageCell.swift

@@ -25,6 +25,7 @@ open class TextMediaMessageCell: MessageContentCell {
         let imageView = UIImageView()
         imageView.contentMode = .scaleAspectFill
         imageView.translatesAutoresizingMaskIntoConstraints = false
+        imageView.clipsToBounds = true
         return imageView
     }()