Describe the bug
Hi,

What is the correct behaviour for isURL function when I give e-mail address? I would expect that return false.

Examples
An example from the Node REPL:

Welcome to Node.js v14.16.0.
Type ".help" for more information.
> var validator = require('validator');
undefined
> validator.isURL('[email protected]');
true
> 

Additional context
Validator.js version: 13.6.0
Node.js version: 14.16.0
OS platform: macOS