remove testcontainers at the end

Author: Alexander Furer

grpc-spring-boot-starter-demo/src/pureNettyTest/resources/bootstrap.yml

@@ -21,3 +21,4 @@ embedded:
       JAVA_OPTS_APPEND: "-Xms1024m -Xmx1024m"
   containers:
     enabled: false
+    force-shutdown: true