This bug introduced a regression whereby if an authorized value has no
branch limitations then the authorized value cannot be edited once it
has been created. The edit page would display an error and not load.
This is the second case of a simple ternary correcting the issue, but
the logic of returning 'undef' from 'get_branch_limits' being called
into question.
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>