tools: Remove logging when parsing args in engine-manage-domains

Removes log messages when parsing args in engine-manage-domains.
This is needed to enable logging setup that uses command line
arguments.

Change-Id: I3b1c5e76e6dbd2bc2c3d49abac03e10d4dc6faf6
Bug-Url: https://bugzilla.redhat.com/1083411
Signed-off-by: Martin Perina <mperina@redhat.com>