Update tests for httpserver.

Author: brian-brazil

jmx_prometheus_javaagent/src/test/java/io/prometheus/jmx/TestApplication.java

@@ -7,5 +7,6 @@ public static void main(String[] args) throws IOException {
         System.out.println();
         System.out.flush();
         System.in.read();
+        System.exit(0);
     }
 }