irc: trigger ScrollTextWidget updateScrollBar after appending to force immediate repaint on send

Signed-off-by: Slendi <slendi@socopon.com>

main.lua

@@ -270,6 +270,10 @@ function IrcChatView:appendLine(line, target)
         if self._ui_open and self.scroll_text_w and self.scroll_text_w.text_widget then
             self.scroll_text_w.text_widget:setText(buf)
             self.scroll_text_w:scrollToBottom()
+            -- Ensure ScrollTextWidget refreshes its scrollbar & triggers a repaint
+            if self.scroll_text_w.updateScrollBar then
+                self.scroll_text_w:updateScrollBar(true)
+            end
             if UIManager and self.frame and self.frame.dimen then
                 UIManager:setDirty(self, function() return "ui", self.frame.dimen end)
             end