Update pom.xml for pipeline

2 jobs for master in 2 minutes and 40 seconds (queued for 24 minutes and 13 seconds)
Status Job ID Name Coverage
  Release
failed #1266248
manual
release/code

00:02:03

 
  Cleanup
passed #1266249
pipeline

00:00:36

 
Name Stage Failure
failed
release/code Release
[ERROR]   The project net.ihe.gazelle:gazelle-webservice-tester:1.7.4 (/builds/gazelle/applications/test-execution/simulator/gazelle-webservice-tester/./pom.xml) has 1 error
[ERROR] 'build.plugins.plugin.version' for org.sonatype.plugins:nexus-staging-maven-plugin must be a valid version but is '${nexus.staging.maven.plugin.version}'. @ line 234, column 30
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/ProjectBuildingException
ERROR: Job failed: command terminated with exit code 1