Images in upload folder not over https

Hello!

We want to present our login page with https. All css are working now, but there is still an ugly security warning from the browser because the images in the upload folder are implemented with http.

For example: https://www.wiseseo.de/anmelden/?version=platin

implements the logo with: http://www.wiseseo.de/wp-content/uploads/2013/08/wise-seo-logo-header.png.

Can you please help me?

Thanks & regards,

Martin