nomad registered service - script check wrongly registered as ttl check

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#### Overview of the Issue

nomad registered service - script check wrongly registered as ttl check
service registered using nomad service, script check registered with raw_exec driver
nomad version 0.10.3
consul version 1.7.2 - enable_script_checks: true
*UI, not showing script output on ttl checks

#### Reproduction Steps

Steps to reproduce this issue, eg:

1.create nomad/consul cluster of 1 in dev mode
2.create dummie job myservice with script check
3.curl -ks http://localhost:8500/v1/health/checks/myservice
type: ttl
### Operating system and Environment details
redhat linux 7
### Log Fragments

Include appropriate Client or Server log fragments. If the log is longer than a few dozen lines, please include the URL to the [gist](https://gist.github.com/) of the log instead of posting it in the issue. Use `-log-level=TRACE` on the client and server to capture the maximum log detail.