Commit ecd954d530 installs specific interface triggers which rewrites the dnsmasq config
file and restarts dnsmasq if the network interface becomes active for which a trigger
has been installed.
In case no dhcp sections are specified or ignore is set to 1 dnsmasq will not be started
at startup which breaks DNS resolving.
Fix this by ditching the BOOT check in start_service and always start dnsmasq at startup.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>