Plugin not HTTPS compatible

The plugin contains hard-coded HTTP URLs for jQuery which cause a mixed-content error on HTTPS sites.

To fix, change lines 263-268 in includes/jquery-colorbox-frontend.php by removing the protocol which is best practice:

if ($this->isTrue('debugMode')) {
    $jQueryLibraryUrl = "//code.jquery.com/jquery-".JQUERYLIBRARY_VERSION.".js";
}
else {
    $jQueryLibraryUrl = "//code.jquery.com/jquery-".JQUERYLIBRARY_VERSION.".min.js";
}