Bug fix issue #1705 full URL support

This will create full URLs when the submission is created with // style hrefs. turns "//i.imgflip.com/df743.jpg" to "https://i.imgflip.com/df743.jpg"
Nit: This line would preferably look like `if (thisHREF.substring(0, 2) === '//') {` (yeah it's really minor).