dnsmasq: always inform about disabled dhcp service

dnsmasq: always inform about disabled dhcp service

Init script checks for an already active DHCP server on the interface
and if such DHCP server is found, then it logs "refusing to start DHCP"
message, starts dnsmasq without DHCP service unless `option force 1` is
set and caches the DHCP server check result.

Each consecutive service start then uses this cached DHCP server check
result, but doesn't provide log feedback about disabled DHCP service
anymore.

So this patch ensures, that the log message about disabled DHCP service
on particular interface is always provided.

Acked-by: Hans Dedecker <dedeckeh@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>