There's a closed pull request on the mblaze repository

seq: fix printing multiple mmsgs
https://github.com/leahneukirchen/mblaze/pull/181

Description:
According to `mseq(1)`, `mseq` should accept multiple *msgs*.

```
printf 'a\nb\n' | mseq -S
mseq 1 2
```

The above prints:
```
a
```