Fix AST parsing for comments

[SebastienGllmt]

Presumably due to a copy-paste mistake, the condition on this flag was the opposite of what it should be.

You can see this function has 3 cases where it looks at compiler flags. The 3rd flag correctly uses not(feature = "lsp"), but the first flag doesn't.

[SebastienGllmt]

Seems the CI fails because of error: package "clap v3.2.17" cannot be built because it requires rustc 1.56.1 or newer, while the currently active rustc version is 1.56.0 which is unrelated to this PR

Seems the fix to that CI issue is included as part of https://github.com/anweiss/cddl/pull/121

[anweiss]

Thanks for this @SebastienGllmt. #121 has been merged. Feel free to rebase.

[SebastienGllmt]

seems there is a new version-related failure in the CI :/

package os_str_bytes v6.3.0 cannot be built because it requires rustc 1.57.0 or newer, while the currently active rustc version is 1.56.1

[anweiss]

Yep. Just bumped the MSRV to 1.57.0 in https://github.com/anweiss/cddl/commit/2464beafb5bbec2ee83fe0303bd5830cd3613759. Try rebasing again.