cmd/sniproxy: Set App name in tsnet hostinfo

Updates #1748
Signed-off-by: Denton Gentry <dgentry@tailscale.com>

cmd/sniproxy/sniproxy.go

@@ -18,6 +18,7 @@ import (
 	"golang.org/x/net/dns/dnsmessage"
 	"inet.af/tcpproxy"
 	"tailscale.com/client/tailscale"
+	"tailscale.com/hostinfo"
 	"tailscale.com/net/netutil"
 	"tailscale.com/tsnet"
 	"tailscale.com/types/nettype"
@@ -36,6 +37,8 @@ func main() {
 		log.Fatal("no ports")
 	}
 
+	hostinfo.SetApp("sniproxy")
+
 	var s server
 	defer s.ts.Close()