fix: Hop Count is 0 in subscribeCov requests, preventing subscription to virtual devices

[smidv]

Problem Description
When calling the readProperty method to retrieve a property from a virtual BACnet device, the Hop Count field has the value DEFAULT_HOP_COUNT and the property is retrieved correctly.
However, when calling the subscribeCov method to subscribe to property changes on the same virtual device, the Hop Count field has a value of 0, and the subscription cannot be established.
Steps to Reproduce

1. Create a virtual BACnet device (emulator/simulator)
2. Call readProperty to read any property → works correctly, Hop Count = DEFAULT_HOP_COUNT
3. Call subscribeCov to subscribe to property changes → fails, Hop Count = 0
4. No response/timeout from the virtual device

Expected Behavior
The subscribeCov method should use DEFAULT_HOP_COUNT (or allow configuring the Hop Count value) similar to readProperty, allowing successful subscription to virtual devices.
Actual Behavior
The subscribeCov method hardcodes Hop Count = 0, which prevents the subscription from working with virtual devices.
Additional Information
I was unable to find a way to pass a custom Hop Count value to the subscribeCov method. The API does not appear to expose this parameter.

[robertsLando]

PR?

[smidv]

#81

ready

[smidv]

UP