You are using a deprecated resolve URL for Pentaho projects. The correct resolve URL is:

http://nexus.pentaho.org/content/groups/omni

Please refer to the official Pentaho Documentation on how to build Pentaho projects with Maven:

https://github.com/pentaho/maven-parent-poms/wiki

This is a sample settings.xml file that could be used in your local build environment:

https://github.com/pentaho/maven-parent-poms/blob/master/maven-support-files/settings.xml