[grid] Only start the standalone server once

Author: shs96c

java/server/src/org/openqa/selenium/grid/commands/Standalone.java

@@ -180,7 +180,6 @@ protected void execute(Config config) {
     Require.nonNull("Config", config);
 
     Server<?> server = asServer(config).start();
-    server.start();
 
     BuildInfo info = new BuildInfo();
     LOG.info(String.format(