Max attempts ignored when guard exists

Example:

```YAML
spec:
phases:
phase1:
steps:
- pub:
chan: mother
payload:
make:
name: shell
type: cmd
config:
command: bash
- recv:
chan: mother
pattern:
success: true
- pub:
payload: |
echo '{"statuscode":200,"body":{"activities":1}}'
- recv:
chan: shell
attempts: 1
pattern:
statuscode: 200
body:
activities: "?activities"
guard: |
return bindings["?activities"] >= 2;
```

This test should fail (without timing out). Instead it hangs. If the guard is removed (and the `recv` body is altered to prevent a match), the test fails immediately as it should.