update hub_url to hub_urls to match zos-config

Author: Eslam-Nawara

pkg/environment/config.go

@@ -39,8 +39,8 @@ type Config struct {
 	BinRepo       string   `json:"bin_repo"`
 	GeoipURLs     []string `json:"geoip_urls"`
 
-	HubURL   []string `json:"hub_url"`
-	V4HubURL []string `json:"v4_hub_url"`
+	HubURL   []string `json:"hub_urls"`
+	V4HubURL []string `json:"v4_hub_urls"`
 
 	// we should not be supporting flist url or hub storage from zos-config until we can update them on runtime
 	FlistURL     string `json:"flist_url"`