When the library matching the current selection is unchecked in the normal editor for library transfer rules, it will be saved correctly, but will still display as checked after saving. 

To test:
* Set UseBranchTransferLimits to enforce
* Go to administration > library transfer limits
* Pick a library, unselect all using the link on top and save
* Verify that the library matching your selection is still displaying as checked
  You can verify that the rule actually appears in:
  select * from branch_transfer_limits;
* Edit the rules again, unselect all and then recheck the library matching the      selected library manually. 
  Rerunning the SQL from before will show the rule is now gone:
  select * from branch_transfer_limits;