fix /plaintext error in CI: "Hello World!" should be "Hello, World!"

frameworks/Java/act/src/main/resources/conf/prod/app.properties

@@ -1,3 +1,2 @@
 http.port=8080
-cli.port=8081
-
+cli.port=8081

frameworks/Java/act/src/main/resources/routes.conf

@@ -1 +1 @@
-GET /plaintext echo: Hello World!
+GET /plaintext echo: Hello, World!