revert: ApplicationBootstrap: enable headless mode."

Spring Boot enables headless mode by default:
spring-projects/spring-boot@e3b352e

This reverts commit c9dfb75.

Author: php-coder

Diff for: src/main/java/ru/mystamps/web/support/spring/boot/ApplicationBootstrap.java

@@ -40,8 +40,6 @@
 public class ApplicationBootstrap {
 
 	public static void main(String... args) {
-		System.setProperty("java.awt.headless", "true");
-		
 		ConfigurableApplicationContext context =
 			SpringApplication.run(ApplicationBootstrap.class, args);