allow oracle connexion through "insecure url" (!250)

* allow connexion to "insecure url"

(cherry picked from commit d549b744)

distance-oracle/src/api.rs

@@ -26,7 +26,7 @@ pub type AccountId = subxt::utils::AccountId32;
 pub type IdtyIndex = u32;
 
 pub async fn client(rpc_url: String) -> Client {
-    Client::from_url(rpc_url)
+    Client::from_insecure_url(rpc_url)
         .await
         .expect("Cannot create RPC client")
 }