Extension validity check not updated on language changed in create plugin dialog.

[jmb462]

Godot version

Master Branch (468b987)

System information

Windows 10, Ubuntu Budgie

Issue description

When creating a plugin with the "Create a plugin" dialog, script name extension is checked and compared with the language selected.

It shows a warning if extension do not match with selected language.

The issue is that the warning is not updated on language change.

Steps to reproduce

• Open the "Create a plugin" dialog (Project Settings > Plugin > Create)
• Choose GDScript language.
• Enter a script name finishing with .gd extenstion

=> The script name is validated. A green check is shown.

• Change the language to VisualScript

=> The green check is still shown but the script name should end with .vs extension now.

Minimal reproduction project

N/A