Update gsnedders' name

Author: gsnedders

.mailmap

@@ -1,2 +1,4 @@
 Andreas Tolfsen <ato@sny.no> <andreastt@opera.com>
 <ato@sny.no> <ato@mozilla.com>
+
+Sam Sneddon <me@gsnedders.com>

index.html

@@ -9155,7 +9155,6 @@ <h2>Acknowledgements</h2>
 <!-- Eran Messeri --> Eran Messeri,
 <!-- Erik Wilde --> Erik Wilde,
 <!-- Gábor Csárdi --> Gábor Csárdi,
-<!-- Geoffrey Sneddon --> Geoffrey Sneddon,
 <!-- Henrik Skupin --> Henrik Skupin,
 <!-- James Graham --> James Graham,
 <!-- Jason Juang --> Jason Juang,
@@ -9172,6 +9171,7 @@ <h2>Acknowledgements</h2>
 <!-- Mike Pennisi --> Mike Pennisi,
 <!-- Ondřej Machulda --> Ondřej Machulda,
 <!-- Randall Kent --> Randall Kent,
+<!-- Sam Sneddon --> Sam Sneddon,
 <!-- Seva Lotoshnikov --> Seva Lotoshnikov,
 <!-- Simon Stewart --> <a href=http://www.rocketpoweredjetpants.com/>Simon Stewart</a>,
 <!-- Titus Fortner --> Titus Fortner,