add public chain4all service url

src/assets/config.json

@@ -1,5 +1,5 @@
 {
-    "CHAIN4ALL_SERVICE_URL": "http://localhost:3000",
+    "CHAIN4ALL_SERVICE_URL": "https://chain4all.lesprojekt.cz",
     "IROHA_ADDRESS": "http://10.0.0.156:8080",
     "ASSET": "coin#test",
     "ADMIN_USER": "admin@test"