broken tests because jmx control port is in use

Executing 'sh' with arguments:
'-f'
'start_xwiki.sh'
'8080'
'8079'
'-Djava.net.preferIPv4Stack=true'
'-Dcom.sun.management.jmxremote'
'-Dcom.sun.management.jmxremote.port=6666'
'-Dcom.sun.management.jmxremote.authenticate=false'
'-Dcom.sun.management.jmxremote.ssl=false'

The ' characters around the executable and arguments are
not part of the command.
Starting Jetty on port 8080 ...
Logs are in the ./xwiki.log file
Error: Exception thrown by the agent : java.rmi.server.ExportException: Port already in use: 6666; nested exception is: 
	java.net.BindException: Address already in use
Result: 1
Failed to start XWiki in [120] seconds, last error code [-1, message []