Abort if tests for disk templates remote_raid1 and drbd are enabled.

Reviewed-by: iustinp

qa/qa_config.py

@@ -51,6 +51,11 @@ def Validate():
   if len(cfg['instances']) < 1:
     raise qa_error.Error("Need at least one instance")
 
+  if (TestEnabled('instance-add-remote-raid-disk') and
+      TestEnabled('instance-add-drbd-disk')):
+    raise qa_error.Error('Tests for disk templates remote_raid1 and drbd'
+                         ' cannot be enabled at the same time.')
+
 
 def get(name, default=None):
   return cfg.get(name, default)