Delete headless

settings.gradle

@@ -5,4 +5,4 @@ plugins {
 // A list of which subprojects to load as part of the same larger project.
 // You can remove Strings from the list and reload the Gradle project
 // if you want to temporarily disable a subproject.
-include 'core', 'android', 'ios', 'headless', 'lwjgl3'
+include 'core', 'android', 'ios', 'lwjgl3'