Clover plugin fails to reset build directory in clover:off

The clover:on goal resets the maven.build.dest property so that Clover instrumented classes don't get mixed with non-instrumented classes. The old value is saved in a variable "mavenBuildDestOld." The clover:off goal attempts to restore the original maven.build.dest property, but it uses a non-existant variable named "mavenBuildDestTestOld," so the reset fails.

If you are running many Maven goals at once, like a site deploy, this can cause NoClassDefFound errors, since the instrumented clases will continue to be used.