Update 9.0.9 error

When i click on update i get the following error what this means.?

e [GuzzleHttp\Ring\Exception\RingException] e
e cURL error 51: SSL peer certificate or SSH remote key was not OK e

Update:
I try to run the update from command line
sudo -u apache php occ upgrade
i get the following : ownCloud is already latest version
but i still get notificatoin that i need to update to 9.0.9
i am running version : ownCloud 9.0.8 (stable)

any suggestions?

This will only run the database upgrade routine after you have updated the oC code. It won't do that for you.

As the updater app is known to be unreliable just do the manual update as explained in the documentation [1].

[1] https://doc.owncloud.org/server/latest/admin_manual/maintenance/manual_upgrade.html

I currently have 9.0.8 ,Do i have to update to 9.0.9 1st? or can i just update directly to newest version : 9.1.5 ?

Its always advised to go to the latest minor version (in your case 9.0.9) first before going to the next major release (in your case 9.1.5).