Add Even Stensberg to .mailmap

Change-Id: I8d5cd73d6b344f1d9fa4a3527bd88f3d6b3a9aec

.mailmap

diff --git a/.mailmap b/.mailmap
index 8154169..fd187c2 100644
--- a/.mailmap
+++ b/.mailmap
@@ -1 +1,2 @@
-Shawn Pearce <sop@google.com> Shawn O. Pearce <sop@google.com>
+Even Stensberg <evenstensberg@gmail.com> ev1stensberg <evenstensberg@gmail.com>
+Shawn Pearce <sop@google.com>            Shawn O. Pearce <sop@google.com>