After an install or an enable, the next disable will be good, but a second and subsequent disable will have the repeated lines.
# systemctl disable haveged Synchronizing state of haveged.service with SysV init with /lib/systemd/systemd-sysv-install... Executing /lib/systemd/systemd-sysv-install disable haveged insserv: warning: current start runlevel(s) (empty) of script `haveged' overrides LSB defaults (2 3 4 5). insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `haveged' overrides LSB defaults (0 1 6). # systemctl disable haveged Synchronizing state of haveged.service with SysV init with /lib/systemd/systemd-sysv-install... Executing /lib/systemd/systemd-sysv-install disable haveged insserv: warning: current start runlevel(s) (empty) of script `haveged' overrides LSB defaults (2 3 4 5). insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `haveged' overrides LSB defaults (0 1 6). insserv: warning: current start runlevel(s) (empty) of script `haveged' overrides LSB defaults (2 3 4 5). insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `haveged' overrides LSB defaults (0 1 6).