Make "litecoin" filled instead of outlined

[ondrejnedoma]

Before submitting a new icon request, please confirm the following:

• [X] I have searched all issues to make sure there isn't a request for this icon.
• [X] I have searched the current library to make sure the icon doesn't already exist.
• [X] I understand that brand icons are no longer being added and I can use SimpleIcons for my brand icon needs.
• [X] I only intend to request a single icon (or a few near-identical ones) in this issue.

What would you use this icon for?

Currently, the 3 crypto icons are bitcoin, ethereum and litecoin. litecoin is the only one which is outlined and not filled, and it looks incosistent next to bitcoin and ethereum

Give us an example of what this icon might look like.

Just make it filled. That's it