fix: update go-c8y lib to fix notifications2 connect/reconnect errors

[reubenmiller]

Fixes to the c8y notification2 commands regarding the websocket connection to Cumulocity IoT and the parsing of the messages.

Changes include:

• Fix message parsing bug which was caused by failing to allocate memory during parsing which resulted in corrupted message parsing (fields were mixed). This would result in corrupted ack messages which the server would then disconnect the client, and a reconnection loop would start.
• Update websocket library to prevent use of closed network connection errors
• Explicitly close websocket before reconnecting