use switch to check for error of type ActivationServiceError

pkg/substrate_gateway/substrate_gateway.go

@@ -57,12 +57,16 @@ func (g *substrateGateway) EnsureAccount(activationURL []string, termsAndConditi
 		Msg("method called")
 	g.mu.Lock()
 	defer g.mu.Unlock()
+
 	for _, url := range activationURL {
 		info, err = g.sub.EnsureAccount(g.identity, url, termsAndConditionsLink, termsAndConditionsHash)
 		// check other activationURL only if EnsureAccount failed with ActivationServiceError
-		if errors.Is(err, substrate.ActivationServiceError{}) {
-			log.Debug().Str("activation url", url).Err(err).Msg("failed to EnsureAccount with ActivationServiceError")
-			continue
+		if err != nil {
+			switch err.(type) {
+			case substrate.ActivationServiceError:
+				log.Debug().Str("activation url", url).Err(err).Msg("failed to EnsureAccount with ActivationServiceError")
+				continue
+			}
 		}
 		return
 	}