Icons not showing after going from local to server

Hi everyone!

I have this problem after going from local (xampp) to live server. Basically every icon on the website ( icon of the theme, icon of drupal toolbar) aren't showing.
After some investigation i understood that there's a problem with the directory of the images because after inspecting one of them i've seen that the icons are actually there, but the URL of background-image have the old local domain name.

Ex:
How it is now: background-image: url(/oldname/core/themes/stable/images/core/icons/787878/file.svg);
How it should be: background-image: url(/newname/core/themes/stable/images/core/icons/787878/file.svg);

I had similar problem before also with the logo image and some other but after going to /admin/config/media/file-system and saving the configuration everything has returned to normal.
There's some way to update the directory of the icon's images in order to change those wrong URL?
I already tried searching for similar problems on internet but nothing seems to fix my problem, i also tried installing some module (Pathologic) that should avoid broken links and incorrect paths in content.

Thanks everyone in advance :)