Reset continue button state when dismissing registration number confirmation dialog.

app/src/main/java/org/thoughtcrime/securesms/registration/fragments/RegistrationViewDelegate.kt

@@ -58,6 +58,7 @@ object RegistrationViewDelegate {
       setMessage(message)
       setPositiveButton(android.R.string.ok) { _, _ -> onConfirmed.run() }
       setNegativeButton(R.string.RegistrationActivity_edit_number) { _, _ -> onEditNumber.run() }
+      setOnDismissListener { onEditNumber.run() }
     }.show()
   }
 }