/usr/share/caja-python/extensions/syncstate-Nextcloud.py produces many error lines in .xsession-errors

[Norbert]

Steps to reproduce:
1. Install Caja Nextcloud by

    sudo apt-get install caja-nextcloud

2. Restart Caja

    caja -q

3. Open Caja and watch the contents of .xsession-errors from terminal with

    tail -f ~/.xsession-errors

Expected results:
* log is almost empty

Actual results:
* Nextcloud generates many equal lines like shown below

Traceback (most recent call last):
  File "/usr/share/caja-python/extensions/syncstate-Nextcloud.py", line 232, in get_file_items
    return self.ask_for_menu_items(files)
  File "/usr/share/caja-python/extensions/syncstate-Nextcloud.py", line 249, in ask_for_menu_items
    if not socketConnect.read_socket_data_with_timeout(timeout - dt):
  File "/usr/share/caja-python/extensions/syncstate-Nextcloud.py", line 122, in read_socket_data_with_timeout
    self._remainder += self._sock.recv(1024)
OSError: [Errno 22] Invalid argument

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: caja-nextcloud 3.1.1-1ubuntu1.1
ProcVersionSignature: Ubuntu 5.11.0-25.27-generic 5.11.22
Uname: Linux 5.11.0-25-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: MATE
Date: Sat Aug 7 11:34:30 2021
InstallationDate: Installed on 2021-04-23 (105 days ago)
InstallationMedia: Ubuntu-MATE 21.04 "Hirsute Hippo" - Release amd64 (20210420)
PackageArchitecture: all
SourcePackage: nextcloud-desktop
UpgradeStatus: No upgrade log present (probably fresh install)