Discovery messages for non-namespaced components cause errors

[bergie]

The MicroFlo MsgFlo compatibility mode (see microflo/microflo#143) makes participants that don't have a namespace. This causes errors within MsgFlo:

Participant discovery failed: Cannot set property 'definition' of undefined
TypeError: Cannot set property 'definition' of undefined
   at Library._updateComponents (/opt/c-flo/node_modules/msgflo/lib/library.js:262:36)
   at Library._updateDefinition (/opt/c-flo/node_modules/msgflo/lib/library.js:297:17)
   at Coordinator.updateParticipant (/opt/c-flo/node_modules/msgflo/lib/coordinator.js:306:18)
   at Coordinator.participantDiscovered (/opt/c-flo/node_modules/msgflo/lib/coordinator.js:284:19)
   at Coordinator.handleFbpMessage (/opt/c-flo/node_modules/msgflo/lib/coordinator.js:261:19)
   at broker.subscribeParticipantChange (/opt/c-flo/node_modules/msgflo/lib/coordinator.js:221:18)
   at MessageBroker._onMessage (/opt/c-flo/node_modules/msgflo-nodejs/lib/mqtt.js:155:20)
   at MqttClient.client.on (/opt/c-flo/node_modules/msgflo-nodejs/lib/mqtt.js:50:21)
   at MqttClient.emit (events.js:159:13)
   at MqttClient._handlePublish (/opt/c-flo/node_modules/mqtt/lib/client.js:905:12)
   at MqttClient._handlePacket (/opt/c-flo/node_modules/mqtt/lib/client.js:301:12)
   at process (/opt/c-flo/node_modules/mqtt/lib/client.js:257:12)
   at Writable.writable._write (/opt/c-flo/node_modules/mqtt/lib/client.js:267:5)
   at doWrite (/opt/c-flo/node_modules/mqtt/node_modules/readable-stream/lib/_stream_writable.js:406:64)
   at writeOrBuffer (/opt/c-flo/node_modules/mqtt/node_modules/readable-stream/lib/_stream_writable.js:395:5)
   at Writable.write (/opt/c-flo/node_modules/mqtt/node_modules/readable-stream/lib/_stream_writable.js:322:11)
{"protocol":"discovery","command":"participant","payload":{"component":"FeinstaubSensor","label":"","icon":"","id":"staub/arboretum","role":"staub/arboretum","outports":[{"id":"temperature","type":"any","queue":"staub/arboretum/temperature"},{"id":"humidity","type":"any","queue":"staub/arboretum/humidity"},{"id":"pm25","type":"any","queue":"staub/arboretum/pm25"},{"id":"pm10","type":"any","queue":"staub/arboretum/pm10"}],"inports":[{"id":"in","type":"any","queue":"staub/arboretum/sampleinterval"},{"id":"in","type":"any","queue":"staub/arboretum/sendinterval"}],"extra":{"lastSeen":"2018-02-25T00:49:09.124Z"}}}