knotd retrying to write value to Thing for all types of error

[jcorde]

knotd tries to write new values to Thing even after receiving a KNOT_ERR_INVALID message.

Retries should be done only in specific cases, such as signal loss or when explicitly told to do so.

This leads to extra effort trying to do something that is impossible.

[jcorde]

As pointed by @ramonhpr , this is probably related to the property_changed callback at msg.c.

[jcorde]

Also, it's suggested to create another error type like KNOT_ERR_TRY_AGAIN on knot_protocol, something similar to KNOT_ERR_INVALID.

This message will be sent by the thing. The knotd will get this message and know that it should try again. If receiving something like KNOT_ERR_INVALID, it should try again.

[jcorde]

Of course, the knot thing should select the fit message to each found error

[ramonhpr]

@vitbaq @alla3 Since we removed the function property_changed we should verify if the error keeps happening.

[ramonhpr]

@jcorde How can we reproduce this issue?