add versus to undertow in the benchmark_config.json file

frameworks/Java/act/benchmark_config.json

@@ -19,7 +19,7 @@
       "database_os": "Linux",
       "display_name": "actframework",
       "notes": "",
-      "versus": ""
+      "versus": "undertow"
     },
     "pgsql": {
       "setup_file": "setup-postgresql",
@@ -41,7 +41,7 @@
       "database_os": "Linux",
       "display_name": "actframework-pgsql",
       "notes": "",
-      "versus": ""
+      "versus": "undertow"
     },
     "mysql": {
       "setup_file": "setup-mysql",
@@ -63,7 +63,7 @@
       "database_os": "Linux",
       "display_name": "actframework-mysql",
       "notes": "",
-      "versus": ""
+      "versus": "undertow"
     },
     "mongodb": {
       "setup_file": "setup-mongodb",
@@ -85,7 +85,7 @@
       "database_os": "Linux",
       "display_name": "actframework-mongo",
       "notes": "",
-      "versus": ""
+      "versus": "undertow"
     }
   }]
 }