The Override method is mainly for use in a manual call of ddnssync where one
wants to manually override (force) the IP address to use in the DNS update.

You cannot use the override method within an INI file, it can only be invoked
via the command line as follows:

ddnssync -i 1.2.3.4

By invoking ddnssync with the -i option, you are forcing ddnssync to 
'determine' your IP address as 1.2.3.4 and act accordingly.  If the specified
address is different than the last address detected by ddnssync then an update
of your domain records will be performed using the address specified on the
command line.  If the specified address is the same as the last detected one
then ddnssync will do whatever it would do depending on the service (in most
cases nothing will be done if ddnssync determines your IP address hasn't 
changed).