[stable/rabbitmq] Rename RABBITMQ_VHOST (#2853)

* Rename RABBITMQ_VHOST

Rename RABBITMQ_VHOST to RABBITMQ_DEFAULT_VHOST to work with latest rabbitmq:3 images. 
Source: https://hub.docker.com/_/rabbitmq/

* Bump rabbitmq chart version

stable/rabbitmq/Chart.yaml

@@ -1,5 +1,5 @@
 name: rabbitmq
-version: 0.6.12
+version: 0.6.13
 appVersion: 3.6.14
 description: Open source message broker software that implements the Advanced Message Queuing Protocol (AMQP)
 keywords:

stable/rabbitmq/templates/deployment.yaml

@@ -38,7 +38,7 @@ spec:
           value: {{ printf "%s@%s" (default "rabbit" .Values.rabbitmqNodeName) "localhost" | quote }}
         - name: RABBITMQ_CLUSTER_NODE_NAME
           value: {{ default "" .Values.rabbitmqClusterNodeName | quote }}
-        - name: RABBITMQ_VHOST
+        - name: RABBITMQ_DEFAULT_VHOST
           value: {{ default "/" .Values.rabbitmqVhost | quote }}
         - name: RABBITMQ_MANAGER_PORT_NUMBER
           value: {{ default "15672" .Values.rabbitmqManagerPort | quote }}