nsd-4.1.15: problems parsing a zone file

Hi,

after updating nsd from version 4.1.14 to version 4.1.15 I have the
following error messages in the nsd logfile upon startup:


[2017-02-27 10:09:12.347] nsd[18850]: notice: nsd starting (NSD 4.1.15)
[2017-02-27 10:09:12.348] nsd[18852]: error: home.mydomain.org.zone:8:
serial is expected 
[2017-02-27 10:09:12.348] nsd[18852]: error: home.mydomain.org.zone:13:
zone configured as 'home.mydomain.org' has no SOA record. 
[2017-02-27 10:09:12.348] nsd[18852]: error: zone home.mydomain.org
file home.mydomain.org.zone read with 2 errors 
[2017-02-27 10:09:12.360] nsd[18852]: notice: nsd started (NSD 4.1.15),
pid 18851


The same zone file was read without errors with nsd-4.1.14 and older
versions:

[2017-02-27 09:38:22.128] nsd[17816]: notice: nsd starting (NSD 4.1.14)
[2017-02-27 09:38:22.140] nsd[17818]: notice: nsd started (NSD 4.1.14),
pid 17817

nsd-checkzone from version 4.1.15 also reports the above errors whereas
nsd-checkzone from 4.1.14 does not report any errors.

Here is the corresponding zone file:


# cat /var/lib/nsd/home.mydomain.org.zone 
$TTL 600
@ IN SOA ns4.mydomain.org. polynomial-c.gmx.de. (
    201702270932        ; Serial
    14400               ; Refresh
    1800                ; Retry
    604800              ; Expire
    86400               ; Minimum
    )

@               IN NS   ns4.mydomain.org.

@               IN A    85.212.112.110


I am quite new to DNS servers and its configuration so it might also be
my config being broken. But searching the web and reading the
documentation didn't bring me to a working solution so now I'm here :)

Please CC me on replies as I am not subscribed to this list.

Thanks in advance
kind regards
Lars