caddyfile: Allow heredoc blank lines

[armadi1809]

Closes #6048

@francislavoie. This seemed quick, so I thought I would take a crack at it.

[francislavoie]

We need tests to cover this.

[francislavoie]

I don't think it's valid to have partial whitespace on the line, that's weird. Also I don't think we should remove whitespace if they include it (the whitespace may be important to the user, it should be preserved).

[armadi1809]

So what you're saying is no need to account for the fact where the blank line is not really empty but contains whitespaces? Also, I thought I am not removing any whitespaces as I am only checking for the output of the TrimSpace function but not assigning it to anything.

[francislavoie]

I think a heredoc indented with 2 tabs, having an "empty" line with only 1 tab, is not valid.

I also think a heredoc with 2 tabs, having an "empty" line with 3 tabs is valid, and it should preserve that 1 tab as real text (after stripping the leading 2 tabs)

[armadi1809]

@francislavoie I think it should now cover the cases you mentioned. I also added test cases but please let me know if we need more. Thanks.

[armadi1809]

All the feedback items above should now be resolved. Thank you for your prompt feedback @francislavoie!

[francislavoie]

Great, thanks!

[francislavoie]

Hmm, the CLA bot is down, I think. I guess we'll have to wait for it to wake up 😂 but that's fine