Ignore --protect-args when already sent by client

Ignore --protect-args when already sent by client

In parse_arguments when --protect-args is encountered the function exits
early. The caller is expected to check protect_args, and recall
parse_arguments setting protect_args to 2. This patch prevents the
client from resetting protect_args during the second pass of
parse_arguments. This prevents parse_arguments returning early the
second time before it's able to sanitize the arguments it received.