fix error with older findbugs plugin
fix error with older findbugs plugin

Findbugs plugin version 3.0.0 can produce this:

[ERROR] Failed to execute goal org.codehaus.mojo:findbugs-maven-plugin:3.0.0:findbugs (default) on project hbase: Unable to parse configuration of mojo org.codehaus.mojo:findbugs-maven-plugin:3.0.0:findbugs for parameter pluginArtifacts: Cannot assign configuration entry 'pluginArtifacts' with value '${plugin.artifacts}' of type java.util.Collections.UnmodifiableRandomAccessList to property of type java.util.ArrayList -> [Help 1]

Fix is to upgrade the plugin from 3.0.0 to 3.0.4. 

https://issues.apache.org/jira/browse/HBASE-21696
eis/minimal-di,eis/minimal-di,eis/minimal-di