Description of problem:
confusing windowns when auto-attaching in GUI without manifest uploaded in satellite server.

Version-Release number of selected component (if applicable):
subscription management server: 2.2.0.66-Unknown
subscription management rules: 5.16
subscription-manager: 1.15.9-6.el7
python-rhsm: 1.15.4-2.el7


How reproducible:
always

Steps to Reproduce:
1. Open subscription-manager-gui, and register and auto-attach to a satellite6.1 server which is without manifest uploaded.

2. A window notes that 'no available service level for the installed product', and please see attachment '1.png'. I think it is a good notice.

3. Click 'OK' button in step 2, and a window notes that Registration is done(see attachment 2 [details].png). I think it is also Okay.


4. Click 'Next' button in step 3, 'Confirm Subscriptions' window displayed. Please see attachment 3 [details].png.

1) The field 'Using service level' is displayed 'SLA'. I think it should be blank or a specified sla value.

2) As there is no available sla, the 'Attach' button should be disabled.

5. Click the 'Attach' button, and an error subscribing notice prompts. I think the notice should be more readable. Please see attachment 4 [details].png.

6. Click 'OK' button in step 5, and a registration with activation key is displayed. Please see attachment 5 [details].png. The registration is finished in step 1, so I think this is not reasonable.


Actual results:
As step 4, step 5 and step 6

Expected results:
When auto-attaching without available SLAs, just prompt a window to notice the failure to attach.

Additional info: