Skip Sonarqube analysis if SONAR_LOGIN is not defined.

1 job for master in 5 minutes and 59 seconds (queued for 1 second)
Name Stage Failure
failed
build Test
> Task :asm-util:publishMavenJavaPublicationToMavenLocal
> Task :asm-util:publishToMavenLocal

BUILD SUCCESSFUL in 2s
47 actionable tasks: 12 executed, 35 up-to-date
$ if [ $SONAR_LOGIN ]; then '$GRADLE jacocoTestReport sonarqube -Dsonar.host.url=$SONAR -Dsonar.login=${SONAR_LOGIN}'; fi
/usr/bin/bash: line 128: $GRADLE jacocoTestReport sonarqube -Dsonar.host.url=$SONAR -Dsonar.login=${SONAR_LOGIN}: command not found
Cleaning up file based variables
ERROR: Job failed: exit code 1