I dug into the code and found where this error was being added and took out what I thought was the offending bit of code.
However, in doing so, it started adding a <br />
tag.
So, that made me think something else was adding it during the parse. Sure enough, it was wordpress itself. By adding [raw]
tags around my shortcode, it fixed the problem.
Incorrect:
[customcontact form=2]
Correct:
[raw]
[customcontact form=2]
[/raw]