Follow up 20bdc01fa687b174a732be4483ddea4982d67ce9

Fixed scripting deficiency of being unable to tell whether a user is assigned to a specific instance or not ( 20bdc01fa687b174a732be4483ddea4982d67ce9 removed that ability ), because users can be assigned to more than a single instance on hercules, the previous instance_id(<va>) isn't viable, so I'm introducing has_instance2("<map_name>"), returns the instance id of that map for the user (as long as the user is assigned to a instead with that map), -1 upon failure -- valid instance ids are >= 0.

Signed-off-by: shennetsind <ind@henn.et>