[AMBARI-21158] Eliminate Maven warning in Log Feeder Container Registry

[adoroszlai]

What changes were proposed in this pull request?

Get rid of Maven warning:

[WARNING] Some problems were encountered while building the effective model for org.apache.ambari:ambari-logsearch-logfeeder-container-registry:jar:2.0.0.0-SNAPSHOT
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-jar-plugin is missing. @ org.apache.ambari:ambari-logsearch-logfeeder-container-registry:[unknown-version], ambari-logsearch/ambari-logsearch-logfeeder-container-registry/pom.xml, line 73, column 15

How was this patch tested?

$ mvn -am -pl ambari-logsearch/ambari-logsearch-logfeeder-container-registry clean package
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] ambari-logsearch                                                   [pom]
[INFO] Ambari Logsearch Log Feeder Container Registry                     [jar]
...
[INFO] BUILD SUCCESS

[asfgit]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/Ambari-Github-PullRequest-Builder/3610/
Test PASSed.

[oleewere]

lgtm