TestServerAdvancedOps server leaking

When added the testresources added as base class the resource variable usage
changed, and it renamed to os_resources in the other places.

TestServerAdvancedOps still want to use the old variable,
 however the base class has proper tearDownClass method.

Let the TestServerAdvancedOps to use the base class's tearDownClass.

Fixes Bug 1157306

Change-Id: I9bc1c90d526865cafbc6fbf71172aae10e95cb7d
1 file changed