./java.base/share/classes/java/lang/VersionProps.java.template
  
  /**
     * Print version info.
     */
    private static void print(boolean err, boolean newln) {
        boolean isHeadless = false;
        PrintStream ps = err ? System.err : System.out;

        /* Report that we're running headless if the property is true */
        String headless = System.getProperty("java.awt.headless");
        if ( (headless != null) && (headless.equalsIgnoreCase("true")) ) {
            isHeadless = true;
        }

But we never use isHeadless after this.

This is a leftover from Java SE Embedded support - see JDK-8140723 (which should have removed it)