internal/gophers: add new e-mail address

My e-mail address has changed.

Change-Id: I09b1d82dbf2044ab1cd7791a20e24a3e62bf87d0
Reviewed-on: https://go-review.googlesource.com/75030
Reviewed-by: Ian Lance Taylor <iant@golang.org>

internal/gophers/gophers.go

@@ -964,7 +964,7 @@ func init() {
 	addPerson("Michael Matloob", "matloob@golang.org", "matloob@google.com", "@matloob")
 	addPerson("Michael McConville", "momcconville@gmail.com")
 	addPerson("Michael McGreevy", "mcgreevy@golang.org", "@mcgreevy")
-	addPerson("Michael Munday", "munday@ca.ibm.com", "@mundaym")
+	addPerson("Michael Munday", "mike.munday@ibm.com", "munday@ca.ibm.com", "@mundaym")
 	addPerson("Michael Pearson", "mipearson@gmail.com", "@mipearson")
 	addPerson("Michael Pratt", "mpratt@google.com", "@prattmic")
 	addPerson("Michael Schaller", "michael@5challer.de", "@michael-schaller")