ipn/ipnlocal: fix error message typo in ingress peerapi handler

Updates tailscale/corp#7515

Change-Id: I81edd7d9f8958eef61be71d3d34e545cd3347008
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/ipnlocal/peerapi.go

@@ -622,11 +622,11 @@ func (h *peerAPIHandler) handleServeIngress(w http.ResponseWriter, r *http.Reque
 	}
 	target := r.Header.Get("Tailscale-Ingress-Target")
 	if target == "" {
-		bad("Tailscale-Target-Target header not set")
+		bad("Tailscale-Ingress-Target header not set")
 		return
 	}
 	if _, _, err := net.SplitHostPort(target); err != nil {
-		bad("Tailscale-Target-Target header invalid; want host:port")
+		bad("Tailscale-Ingress-Target header invalid; want host:port")
 		return
 	}