Discovered while working on {T347512}
Using a txt spf record as an example, but I was also unable to create cname records. I was unable to create a complete record from the start, so I did this "stub" to verify that I could create a dns record of some kind.
**Steps to replicate the issue** (include links if applicable):
* create a stub spf record that does not contain actionable data
```
twl.wmflabs.org. 60 IN TXT "v=spf1"
```
* try to update the record with actual spf info (note that I've also tried `ip4` in place of `a`)
```
twl.wmflabs.org. 60 IN TXT "v=spf1 a: ip4:185.15.56.1 ~all"
```
**What happens?**:
a 400 error response, with or without info in the body:
response body: `"404 Client Error: NOT FOUND for url: https://openstack.eqiad1.wikimediacloud.org:29001/v2/zones/7c72e06e-3bd6-4512-8176-5c4a0e52e00e/recordsets/3c53c1f4-3962-45ca-b08e-0310f1a95de2"`
response body from another attempt: `""`
**What should have happened instead?**:
a record update should be saved
**Software version** (skip for WMF-hosted wikis like Wikipedia):
n/a
**Other information** (browser name/version, screenshots, etc.):
example horizon dns form:
{F41560771}
error toast:
{F41560774}