Bug 481794

SUMMARY
***
Setting an http url in the desktop custom location results in an unrecoverable crash that tries to recover but fails. Trying to start plasmshell from the terminal it crashes again.
***


STEPS TO REPRODUCE
1. On Desktop, Right-Click > Configure Desktop and Wallpaper...
2. Select Location from the side bar
3. Select custom location radio button
4. Enter `http://www.duckduckgo.com` where it says in hinted text "Type Path or URL..."
5. Apply/save settings

OBSERVED RESULT
Total plasmashell crash that tries to recover but fails. Subsequent attempts to start plasmashell from terminal also fails

EXPECTED RESULT
Not sure, the hinted text did say URL and trying KDE for the first time, I am not sure if there is a support for online links.
So either reject http urls and all invalid urls and remove the hint to "URL...", or support it somehow i guess 

SOFTWARE/OS VERSIONS
Windows: false
macOS: false
Linux/KDE Plasma: True
(available in About System)
KDE Plasma Version: 5.27.10
KDE Frameworks Version: 5.114.0
Qt Version: 5.15.12

ADDITIONAL INFORMATION

Manual Recovery:
Edit the `plasma-org.kde.plasma.desktop-appletsrc` under `~/.config` and find the url that should be present there and remove it.

Developer Information:
```
Application: Plasma (plasmashell), signal: Segmentation fault

[KCrash Handler]
#4  0x00007fb2a4b7d0ea in ?? () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#5  0x00007fb2a4b71d59 in ?? () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#6  0x00007fb2a52f4db4 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fb2a4b1cecb in KIO::ListJob::redirection(KIO::Job*, QUrl const&) () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#8  0x00007fb2a52f4db4 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007fb2a4b052b9 in KIO::SlaveInterface::redirection(QUrl const&) () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#10 0x00007fb2a4b07478 in KIO::SlaveInterface::dispatch(int, QByteArray const&) () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#11 0x00007fb2a4b054bd in KIO::SlaveInterface::dispatch() () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#12 0x00007fb2a4b099f2 in KIO::Slave::gotInput() () from /lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#13 0x00007fb2a52f4db4 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#14 0x00007fb2a52ea85e in QObject::event(QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#15 0x00007fb2a616c783 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Widgets.so.5
#16 0x00007fb2a52bd30a in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007fb2a52c0407 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007fb2a53171a7 in ?? () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#19 0x00007fb2a3f19d3b in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007fb2a3f6f258 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007fb2a3f173e3 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007fb2a53167f8 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007fb2a52bbc2b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x00007fb2a52c41d4 in QCoreApplication::exec() () from /lib/x86_64-linux-gnu/libQt5Core.so.5
#25 0x00005654282e9a8b in ?? ()
#26 0x00007fb2a4829d90 in __libc_start_call_main (main=main@entry=0x5654282e8b70, argc=argc@entry=1, argv=argv@entry=0x7ffc88f089b8) at ../sysdeps/nptl/libc_start_call_main.h:58
#27 0x00007fb2a4829e40 in __libc_start_main_impl (main=0x5654282e8b70, argc=1, argv=0x7ffc88f089b8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffc88f089a8) at ../csu/libc-start.c:392
#28 0x00005654282e9bb5 in ?? ()
[Inferior 1 (process 90066) detached]
```