differentiate the display_name of different otavia variants

Author: alphaho

frameworks/Scala/otavia/benchmark_config.json

@@ -21,7 +21,7 @@
         "webserver": "None",
         "os": "Linux",
         "database_os": "Linux",
-        "display_name": "otavia",
+        "display_name": "otavia (poolSize = 56)",
         "notes": "",
         "versus": "Otavia"
       },
@@ -44,7 +44,7 @@
         "webserver": "None",
         "os": "Linux",
         "database_os": "Linux",
-        "display_name": "otavia",
+        "display_name": "otavia (poolSize = 64)",
         "notes": "",
         "versus": "Otavia"
       }