fix(endpoints): delete unused region tag esp (#10087)

Author: OremGLG

endpoints/multiple-versions/container-engine.yaml

@@ -38,7 +38,6 @@ spec:
         app: esp-echo
     spec:
       containers:
-      # [START esp]
       - name: esp
         image: gcr.io/endpoints-release/endpoints-runtime:1
         args: [
@@ -47,7 +46,6 @@ spec:
           "--service=SERVICE_NAME",
           "--version=SERVICE_CONFIG_ID",
         ]
-      # [END esp]
         ports:
           - containerPort: 8081
       - name: echo