httpserver: Fix test that relies on external DNS lookup

Apparently Cloudflare just caused 1.1.1.1 to resolve, so we have to
change our test IP, hopefully this is better

caddyhttp/httpserver/tplcontext_test.go

@@ -277,7 +277,7 @@ func TestHostname(t *testing.T) {
 		// // Test 3 - ipv6 without port and brackets
 		// {"2001:4860:4860::8888", "google-public-dns-a.google.com."},
 		// Test 4 - no hostname available
-		{"1.1.1.1", "1.1.1.1"},
+		{"0.0.0.0", "0.0.0.0"},
 	}
 
 	for i, test := range tests {