mailmap: change primary address for Jonathan Tan

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: jonathantanmy

.mailmap

@@ -126,6 +126,7 @@ Jon Loeliger <jdl@jdl.com> <jdl@freescale.org>
 Jon Seymour <jon.seymour@gmail.com> <jon@blackcubes.dyndns.org>
 Jonathan Nieder <jrnieder@gmail.com> <jrnieder@uchicago.edu>
 Jonathan del Strother <jon.delStrother@bestbefore.tv> <maillist@steelskies.com>
+Jonathan Tan <jonathantanmy@fastmail.com> <jonathantanmy@google.com>
 Josh Triplett <josh@joshtriplett.org> <josh@freedesktop.org>
 Josh Triplett <josh@joshtriplett.org> <josht@us.ibm.com>
 Julian Phillips <julian@quantumfyre.co.uk> <jp3@quantumfyre.co.uk>