Mod:change registries in reference & service to registry

config/testdata/consumer_config.yml

@@ -35,9 +35,7 @@ registries :
 
 references:
   "UserProvider":
-    registries:
-      - "hangzhouzk"
-      - "shanghaizk"
+    registry: "hangzhouzk,shanghaizk"
     filter: ""
     protocol : "dubbo"
     interface : "com.ikurento.user.UserProvider"

config/testdata/consumer_config_with_configcenter.yml

@@ -5,9 +5,7 @@ config_center:
   address: "127.0.0.1"
 references:
   "UserProvider":
-    registries:
-      - "hangzhouzk"
-      - "shanghaizk"
+    registry: "hangzhouzk,shanghaizk"
     filter: ""
     protocol : "dubbo"
     interface : "com.ikurento.user.UserProvider"

config/testdata/provider_config.yml

@@ -27,9 +27,7 @@ registries :
 
 services:
   "UserProvider":
-    registries:
-      - "hangzhouzk"
-      - "shanghaizk"
+    registry: "hangzhouzk,shanghaizk"
     filter: ""
     protocol : "dubbo"
     # equivalent to interface of dubbo.xml