security/sudo: Update to 1.9.15

While here:

• Prevent combination of SSSD and GSSAPI_HEIMDAL because sssd port requires MIT kerberos and it will conflict with heimdal
• Removed SSSD_DEVEL option because sssd-devel port requires sudo and it creates a circular dependency
• Fix OPIE on FreeBSD versions after it was removed from base

Sponsored by: Rubicon Communications, LLC ("Netgate")

(cherry picked from commit dd773c1540388b14692001643e323a556ed2d445)