Update .gitlab-ci.yml - disable sonar

2 jobs for master in 1 minute and 25 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #5359
validate:jdk8

00:00:32

 
  Test
failed #5360
package:jdk8

00:00:53

 
Name Stage Failure
failed
package:jdk8 Test There is an unknown failure, please try again
	at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
... 60 more
40758 [ERROR]
40758 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
40758 [ERROR]
40758 [ERROR] For more information about the errors and possible solutions, please read the following articles:
40758 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException
ERROR: Job failed: exit code 1