Small inaccuracy in the regular expression when extracting a link to a background image.

[rumano]

When a background image is used and an additional effect follows it, the script cannot correctly recognize the link to the image.

example: background-image: url (background.jpg), linear-gradient (rgba (0, 0, 0, 0.55) 0px, rgba (0, 0, 0, 0) 250px);

the code currently uses the following regex: var pattern = /url(['"]?(.+)['"]?)/;

the following code snippet fixes this: var pattern = /url(['"]?(.+)(jpg|jpeg|png|webp|gif|bmp|tiff)['"]?)/;