Description of problem:
The auto attach will pick a improper subscription when there is a better choice.

Version-Release number of selected component (if applicable):
subscription-manager-1.15.9-2.el7.x86_64
subscription-manager-gui-1.15.9-2.el7.x86_64
subscription-manager-initial-setup-addon-1.15.9-2.el7.x86_64
python-rhsm-1.15.4-2.el7.x86_64

How reproducible:
always

Steps to Reproduce:
1.auto attach a subscription
[root@dhcp-129-157 ~]# LANG=en subscription-manager attach --auto


Installed Product Current Status:
Product Name: Red Hat Enterprise Linux Server
Status:       Subscribed



2.See the system status
[root@dhcp-129-157 ~]#subscription-manager status
+-------------------------------------------+
   System Status Details
+-------------------------------------------+
Overall Status: Insufficient

Red Hat Enterprise Linux for Virtual Datacenters, Premium (DERIVED SKU):
- Guest has not been reported on any host and is using a temporary unmapped guest subscription.

3.Remove the subscription
[root@dhcp-129-157 ~]#subscription-manager remove --all
1 subscription removed at the server.
1 local certificate has been deleted.

4.Attach a proper subscription that make the system status current.
[root@dhcp-129-157 ~]# subscription-manager attach --pool=8a99f9814eb7128e014ebf827a467776
Successfully attached a subscription for: Red Hat Enterprise Linux Server, Premium (Physical or Virtual Nodes)

[root@dhcp-129-157 ~]# subscription-manager status
+-------------------------------------------+
   System Status Details
+-------------------------------------------+
Overall Status: Current

Actual results:


Expected results:
The auto attach model should pick the subscription that make the system stauts current if there do have this kind of subscription.

Additional info: