nuageinit.7: fix cloud-config header line

[freebsd_hello.jonathanmatthews.com]

Summary

This updates the nuageinit(7) man page by aligning mentions of the cloud-config header line with the cloud-init documentation[0], removing an unwanted "!" character.

[0] https://docs.cloud-init.io/en/latest/explanation/about-cloud-config.html#how-do-i-create-a-cloud-config-file

Test Plan

• Manually validate change against https://docs.cloud-init.io/en/latest/explanation/about-cloud-config.html#how-do-i-create-a-cloud-config-file
• Manually validate change against the header line expected by libexec/nuageinit/tests/nuageinit.sh

[bapt]

good catch thank you, can you provide me a git format-patch generated file so you can get proper credit ?

[freebsd_hello.jonathanmatthews.com]

In D53706#1226283, @bapt wrote:

good catch thank you, can you provide me a git format-patch generated file so you can get proper credit ?

Absolutely - I started out with git-format-patch output when creating this Differential entry, but it seems to have been swallowed by the service, somewhere along the way.

I've not used this service's UI before - please could you tell me if I should be able to provide it here, somehow; or if you're requesting it out-of-band, via email? (Sorry for the noise!)

[bapt]

sorry this tool is confusing, and swallowing your properly formatted patch, maybe it is just me would do not know how to properly retrieve this patch properly, in the mean time if you can send it to me by email, I will be able to push it straight thanks.

[freebsd_hello.jonathanmatthews.com]

Patch emailed out of band.