You can disable Discord's auto-embed feature at any time through your User Settings.
1. Click the User Settings cog icon in the bottom left corner
2. Select the "Text & Images" Tab. Then, un-check the boxes titled:
1) "When posted as links to chat." and
2) "When upload directly to Discord."
Pro Tip: If you want to cancel an embed for one specific link, you can wrap the link in '< >' tags.