gradle simple-project-staging sample project uses an obsolete version of the nexus-staging-ant-tasks

The build.gradle file in the "simple-project-staging" project in our trial uses version 1.6.1 of the nexus-staging-ant-tasks:

https://github.com/sonatype/nexus-bundles/blob/nexus-2.11.x/assemblies/nexus-trial/src/main/content/trial-evalguide/gradle/simple-project-staging/build.gradle#L51

This causes the sample project to fail with a pretty unhelpful exception when used with Nexus 2.11.3:

• Where:
  Build file 'C:\nexus-evalguide\gradle\simple-project-staging\build.gradle' line: 125

• What went wrong:
  Execution failed for task ':releaseStagingRepository'.
  > java.lang.ArrayIndexOutOfBoundsException: -1

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

I was going to just check in a fix for this, but then I realized there are probably other places in the sample projects using the wrong versions of the staging clients. So someone who is familiar with these needs to check them over.