Bump mongodb from 3.6.3 to 3.6.5 in /docker/modbus-serial

Bumps [mongodb](https://github.com/mongodb/node-mongodb-native) from 3.6.3 to 3.6.5.
- [Release notes](https://github.com/mongodb/node-mongodb-native/releases)
- [Changelog](https://github.com/mongodb/node-mongodb-native/blob/3.6/CHANGES_3.0.0.md)
- [Commits](mongodb/node-mongodb-native@v3.6.3...v3.6.5)

Signed-off-by: dependabot[bot] <support@github.com>

docker/modbus-serial/package.json

@@ -13,7 +13,7 @@
     "@influxdata/influxdb-client": "^1.11.0",
     "ieee754": "^1.1.13",
     "modbus-serial": "^8.0.1",
-    "mongodb": "^3.6.2",
+    "mongodb": "^3.6.5",
     "mqtt": "^4.2.6"
   }
 }