net/http: fix copy-paste error in the ServeTLS docs

Change-Id: Id7f0d978ce5b0471a404d6e6673b789e7db04650
Reviewed-on: https://go-review.googlesource.com/65653
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/net/http/server.go

@@ -2349,7 +2349,7 @@ func Serve(l net.Listener, handler Handler) error {
 	return srv.Serve(l)
 }
 
-// Serve accepts incoming HTTPS connections on the listener l,
+// ServeTLS accepts incoming HTTPS connections on the listener l,
 // creating a new service goroutine for each. The service goroutines
 // read requests and then call handler to reply to them.
 //