Bug fix: client can handle error in worker during etag handshaking

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Bug fix: too early cmd evaluation

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Removed try catch from client - loadbalancer will remove death workers

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Check if worker address was sent

Signed-off-by: selmeci <selmeci.roman@gmail.com>
Request is send only if etag was returned.
Number of attempts to contact worker was increased to 7.

Signed-off-by: selmeci <selmeci.roman@gmail.com>