Wallpapers, dolphin, widget explorer, ...: Every plasma component tested failed to connect to http://download.kde.org/khotnewstuff/servicemenu-providers.xml and give an error message. There is no proxy set, 

Reproducible: Always

Steps to Reproduce:
1. open for example settings for wallpaper
2. choose "load new wallpapers"

Actual Results:  
"Loading of providers from file: http://download.kde.org/ocs/providers.xml failed"

Expected Results:  
The providers list should have been downloaded

xsession-errors:

knewstuff: Initializing KNS3::Engine from ' "servicemenu.knsrc" '
No frame loaded
No frame loaded
No frame loaded
knewstuff: Loading KNewStuff2 config:  "servicemenu.knsrc"
knewstuff: Categories:  ()
knewstuff: Using registry file:  "/home/xxx/.local/share/knewstuff3/servicemenu.knsregistry"
knewstuff: Loading KNS2 registry of files for the component:  "servicemenu"
The file  "/home/xxx/.local/share/knewstuff3/servicemenu.knsregistry"  could not be opened.
knewstuff: loading providers from  "http://download.kde.org/khotnewstuff/servicemenu-providers.xml"
knewstuff: XmlLoader::load(): url:  QUrl("http://download.kde.org/khotnewstuff/servicemenu-providers.xml")
kdeinit5: Got EXEC_NEW '/usr/lib64/qt5/plugins/kf5/kio/http.so' from launcher.
kdeinit5: preparing to launch '/usr/lib64/qt5/plugins/kf5/kio/http.so'
No frame loaded
No frame loaded
No frame loaded
No frame loaded
No frame loaded
No frame loaded
No frame loaded
No frame loaded
No frame loaded
knewstuff: Write registry