ovirt-log-collector:Fix: Ask password before engine log collection.

The Rest-Api password to be asked before collecting the engine log
whenever needed. Currently the password is asked after collecting
engine and postgres data.

Change-Id: I5e49f3196f5dc5076fe784d7819160dba24e0184
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1098029
Signed-off-by: ndarshan <dnarayan@redhat.com>