Remove unnecessary sleep in NetworkCurl. (#1116)

This commit removes a nasty 100ms wait at the end of the NetworkCurl
run loop which resulted that every CURL download took at least 100ms.
Additionally did some cosmetical clean-ups in the logs and in the code
which doesn't alter the logic.

Resolves: OLPEDGE-2405

Signed-off-by: Andrei Popescu <[email protected]>

Author: Andrei Popescu