No update possible

I’m new here. Sorry for my bad english.
I have run owncloud 10.0.6 on a Raspberry (Stretch). I would update to 10.0.7.
If I press the update button, I get the following error:
"cURL error 60: SSL certificate problem: self signed certificate "
Where is the problem?

Thanks computerpap


you seem to have a similar problem like this user here:

here is his solution:

here are the two commands:

occ maintenance:mode --off
occ upgrade

I could not solve the problem yet.
I switched to the directory / var / www / cloud
When I enter "occ maintenance: mode --off", I get the following message:
"Command not found".
I have owncloud installed in the path / var / www / cloud. The default path is / var / www / owncloud.
In which file do I have to adjust the path to find the command?


the command should be like:

sudo -u www-data php occ maintenance: mode --off