Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1892125
Description of problem:

If a host is already disassociated, the text "The list is excluding 1 physical host" is vague as the host is certainty not a physical host. It should clearly mention that the host is already been disassociated.

Steps to Reproduce:
1. navigate to Hosts > All Hosts and select the check box to the left of the host to be disassociated.
2. From the Select Action drop-down menu, select the Disassociate Hosts button.

Actual results:
In the pop-up Disassociate Hosts page, it says "The list is excluding 1 physical host". It makes people think you can not disassociate the host and causes confusion.

Expected results:
We should not allow users to try disassociate hosts that are not associated