Fix syntax errors in benchmark_config for dart-start and dart-stream

dart-start/benchmark_config

@@ -17,7 +17,7 @@
       "db_url": "/db-mongo",
       "query_url": "/queries-mongo?queries=",
       "fortune_url": "/fortunes-mongo",
-      "update_url": "/updates-mongo?queries="
+      "update_url": "/updates-mongo?queries=",
       "port": 8080,
       "sort": 246
     }

dart-stream/benchmark_config

@@ -6,7 +6,6 @@
       "json_url": "/json",
       "db_url": "/db",
       "query_url": "/queries?queries=",
-      // "fortune_url": "/fortunes",
       "update_url": "/updates?queries=",
       "plaintext_url": "/plaintext",
       "port": 8080,
@@ -16,8 +15,7 @@
       "setup_file": "setup",
       "db_url": "/db-mongo",
       "query_url": "/queries-mongo?queries=",
-      // "fortune_url": "/fortunes-mongo",
-      "update_url": "/updates-mongo?queries="
+      "update_url": "/updates-mongo?queries=",
       "port": 8080,
       "sort": 246
     }