Fix NPE in follow requests view (#1739)

Fixes #1738

app/src/main/java/com/keylesspalace/tusky/adapter/FollowRequestViewHolder.kt

@@ -23,9 +23,9 @@ internal class FollowRequestViewHolder(itemView: View, private val showHeader: B
         val emojifiedName: CharSequence = CustomEmojiHelper.emojifyString(wrappedName, account.emojis, itemView)
         itemView.displayNameTextView.text = emojifiedName
         if (showHeader) {
-            itemView.notificationTextView.text = itemView.context.getString(R.string.notification_follow_request_format, emojifiedName)
+            itemView.notificationTextView?.text = itemView.context.getString(R.string.notification_follow_request_format, emojifiedName)
         }
-        itemView.notificationTextView.visible(showHeader)
+        itemView.notificationTextView?.visible(showHeader)
         val format = itemView.context.getString(R.string.status_username_format)
         val formattedUsername = String.format(format, account.username)
         itemView.usernameTextView.text = formattedUsername