SPF found invalid because of wrong string concatenation

[WKobes]

See https://dev-docker.internet.nl/mail/wouterkobes.nl/3592/#control-panel-12

Seems like string concat is going wrong:

ip4:136.144.136.1" "1 ip4:136.144.136.17

[bwbroersma]

Great test!

[WKobes]

https://dev1.internet.nl/mail/forumstandaardisatie.nl/5046/#mailauth

[bwbroersma]

@mxsasha: is this related to the new DNS stub resolver, or other SPF changes?