fix accessibilty label for InputTextView

deltachat-ios/Chat/InputBarAccessoryView/InputTextView.swift

@@ -76,6 +76,7 @@ open class InputTextView: UITextView {
         label.text = "Aa"
         label.backgroundColor = .clear
         label.translatesAutoresizingMaskIntoConstraints = false
+        label.isAccessibilityElement = false
         return label
     }()
     
@@ -83,6 +84,7 @@ open class InputTextView: UITextView {
     open var placeholder: String? = "Aa" {
         didSet {
             placeholderLabel.text = placeholder
+            accessibilityLabel = placeholder
         }
     }