update icon: c (original, line)

[weh]

Double check these details before you open a PR

• PR does not match another non-stale PR currently opened
• PR name matches the format new icon: Icon name (versions separated by comma). More details here
• PR's base is the develop branch.
• Your icons are inside a folder as seen here
• SVG matches the standards laid out here
• A new object is added in the devicon.json file at the correct alphabetic position as seen here

**This PR closes **

Link to prove your SVG is correct and up-to-date.

https://www.c-language.org/

fixes the following draft-release issue:

🔧 c

Icon Folder

Issues:

• ❌ plain is used as alias base but is not in versions.svg.

[Snailedlt]

Please update the PR to follow the "update icon: " template :)