fix: allow disabling native transport

https://gravitee.atlassian.net/browse/APIM-11588

Author: jhaeyaert

gravitee-apim-gateway/gravitee-apim-gateway-standalone/gravitee-apim-gateway-standalone-distribution/src/main/resources/config/gravitee.yml

@@ -65,6 +65,9 @@ secrets:
 #      enabled: true
 #      pollIntervalSec: 30
 
+#vertx:
+#  # Native transport is prefered by default but can be disabled in case of network instabilities such as with Azure Private Link.
+#  preferNativeTransport: true
 
 # Gateway HTTP server
 #http: