internal/dl: add thanm to validUser

Change-Id: Ic87f3bf158b573a9773e999d79860fba58f2a92c
Reviewed-on: https://go-review.googlesource.com/c/website/+/332069
Trust: Than McIntosh <thanm@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/internal/dl/dl.go b/internal/dl/dl.go
index 39a54c1..66ad690 100644
--- a/internal/dl/dl.go
+++ b/internal/dl/dl.go
@@ -333,7 +333,7 @@
 // Go release binaries via the /dl/upload endpoint.
 func validUser(user string) bool {
 	switch user {
-	case "amedee", "cherryyz", "dmitshur", "drchase", "heschi", "katiehockman", "mknyszek", "rakoczy", "valsorda":
+	case "amedee", "cherryyz", "dmitshur", "drchase", "heschi", "katiehockman", "mknyszek", "rakoczy", "thanm", "valsorda":
 		return true
 	}
 	return false