git: openjdk/jfx-sandbox: tsayao_gtk4_playground: - use gtk_init

[duke]

Changeset: adb291a9
Author:    Thiago Milczarek Sayão <thiago.sayao at gmail.com>
Date:      2021-10-06 16:01:38 +0000
URL:       https://git.openjdk.java.net/jfx-sandbox/commit/adb291a945f73d750421c5bde2d7cf615ef8cdb5

- use gtk_init

! modules/javafx.graphics/src/main/native-glass/gtk4/GlassApplication.cpp