SUMMARY

When dropping a sftp folder in dolphin sidebar, I get the following crash:

```
Application: kioslave5 (kioslave5), signal: Segmentation fault
Content of s_kcrashErrorMessage: {_M_t = {<std::__uniq_ptr_impl<char, std::default_delete<char []> >> = {_M_t = std::tuple containing = {[1] = 0x0, [2] = {<No data fields>}}}, <No data fields>}}
[KCrash Handler]
#6  0x00007f693a6bec4a in sftp_close () from /usr/lib/libssh.so.4
#7  0x00007f693fa422bf in SFTPInternal::close (this=0x55a5de333920) at /usr/src/debug/kio-extras-22.03.80/sftp/kio_sftp.cpp:1198
#8  SFTPInternal::mimetype (url=..., this=0x55a5de333920) at /usr/src/debug/kio-extras-22.03.80/sftp/kio_sftp.cpp:1868
#9  SFTPSlave::mimetype (this=0x7ffca8f9aa10, url=...) at /usr/src/debug/kio-extras-22.03.80/sftp/kio_sftp.cpp:2328
#10 0x00007f693f92a89f in KIO::SlaveBase::dispatch (this=0x7ffca8f9aa10, command=70, data=...) at /usr/src/debug/kio-5.92.0/src/core/slavebase.cpp:1264
#11 0x00007f693f923126 in KIO::SlaveBase::dispatchLoop (this=0x7ffca8f9aa10) at /usr/src/debug/kio-5.92.0/src/core/slavebase.cpp:330
#12 0x00007f693fa426e0 in kdemain (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/kio-extras-22.03.80/sftp/kio_sftp.cpp:92
#13 0x000055a5dd9d720a in main (argc=5, argv=0x7ffca8f9ac88) at /usr/src/debug/kio-5.92.0/src/kioslave/kioslave.cpp:146
[Inferior 1 (process 1143393) detached]
```


STEPS TO REPRODUCE
1. Open a sftp folder
2. Drag a folder to dolphin's sidebar

OBSERVED RESULT
Crash of kio

EXPECTED RESULT
No crash

SOFTWARE/OS VERSIONS
Linux: 5.16.13
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3 + KDE patches

ADDITIONAL INFORMATION