Manual patron block "Save & close" button remains active despite invalid entries

Overview:  Manual patron block "Display description" is the only field required to activate the "Save & close" button, given that "Block actions" are defaulted.  After the "Save & close" button becomes activated, it doesn't gray out even if there is an error.

Steps to Reproduce:

1. Log into Iris BugFest instance as admin
2. Find a user without a patron block
3. Enter a manual patron block and save it
4. Edit the manual patron block you just created
5. Change the "Display description", which will activate the "Save & close"
6. Remove the check marks from all of the "Block actions"
7. Note that this error appears for "Block actions": Select any option

Expected Results:

"Save & close" button becomes deactivated when an error is encountered

Actual Results:

"Save & close" button remains activated despite the error (see attached screen print Save-and-close-button-remains-open.jpg)