hs: Explain why we reset the directory connection timestamp client side
In the v2 HS subsystem we have this in rendclient.c in rend_client_desc_trynow()
:
/* restart their timeout values, so they get a fair shake at
* connecting to the hidden service. */
base_conn->timestamp_created = now;
base_conn->timestamp_lastread = now;
base_conn->timestamp_lastwritten = now;
We've taken the same thing into the v3 client in #17242 (moved) but we need a comment that explains why we do that because get a fair shake
is not very helpful :).