Mailmap: Change Corey Frang's email address.

Author: scottgonzalez

.mailmap

@@ -11,7 +11,7 @@ Ben Hollis <bhollis@amazon.com> <ben@benhollis.net>
 Benjamin Scott Boyle <benjamins.boyle@gmail.com>
 Bert ter Heide <bertjh@hotmail.com>
 Chairat Sunthornwiphat <pipo@sixhead.com>
-Corey Frang <gnarf@gnarf.net>
+Corey Frang <gnarf37@gmail.com> <gnarf@gnarf.net>
 Courtland Allen <courtlandallen@gmail.com>
 Dan Streetman <ddstreet@ieee.org>
 Diego Tres <diegotres@gmail.com>