Added Sentry config to the example config file.

gso/oss-params-example.json

@@ -122,5 +122,9 @@
     "ASN": 137,
     "snmp_community": "secret community string",
     "md5_password": "snmp password"
+  },
+  "SENTRY": {
+    "DSN": "https://sentry-dsn-url",
+    "environment": "development"
   }
 }