Revert "Fix typo in writing vm-group hash to individual test definition."
Revert "Fix typo in writing vm-group hash to individual test definition."

Only target_group is actually supported within the dispatcher.
The original change disables all vm_group operations.

This reverts commit 9469e1182096513f58317edbbc5bff9ea1b48cb6.

Change-Id: I44bec33da19f507acb5250df89b0ed0ff2dad0f2
Linaro/lava-server,Linaro/lava-server,OSSystems/lava-server,Linaro/lava-server,Linaro/lava-server,OSSystems/lava-server,OSSystems/lava-server