Log WARN if wildfly.config.url is set on the server.

-Dwildfly.config.url=wildfly-config.xml can be set to specify configuration to be used , this should typically only be used for a standalone JVM application, not when running EAP.  If this system property is set when starting EAP, it will overrule the configuration in the JBoss Profile xml.  Logging a WARN when this is set inside of EAP would warn the user that their JBoss Profile xml configuration is not being used.

Steps to test:

• Create wildfly-config.xml in JBOSS_HOME
• Start the server: ./standalone.sh -Dwildfly.config.url=wildfly-config.xml
• Verify that the following warning is in server.log

  2021-01-23 09:41:04,669 WARN  [org.jboss.as.config] (MSC service thread 1-2) WFLYSRV0281: System property wildfly.config.url = wildfly-config.xml is set. This should only be used for standalone clients. Setting this on the server will override your profile configuration.