Fix "version missing" warning at the beginning of Maven builds

Steps to reproduce:
1. Start a Maven build

Actual Results:
A warning is printed at the beginning:

'build.plugins.plugin.version' for org.apache.maven.plugins:maven-install-plugin is missing

This is OK for normal, manual builds, but it makes the build fail in other, less-tolerant systems like Jenkins.

Expected Results:
No warnings should be printed. Maven plugin versions should be correctly indicated in the pom files

Workaround (if any):