Serverless cannot fetch git functions from private repos via SSH key

[kwiatekus]

Description

When trying to fetch git functions from private git repositories via SSH key controller fails with error

{"level":"ERROR","timestamp":"2023-05-18T03:10:30Z","logger":"controllers.function","caller":"git/fetcher.go:43","message":"failed to open existing repo at [/tmp/ab9e7b971eddb3f10b00175c2fe79daa]: could not find repository from '/tmp/ab9e7b971eddb3f10b00175c2fe79daa'","context":{"kind":"Function","name":"github-func","namespace":"test-serverless-gitauth-03h10m00s","version":1}}
{"level":"ERROR","timestamp":"2023-05-18T03:10:30Z","logger":"controllers.function","caller":"git/fetcher.go:52","message":"failed to use existing origin remote at [/tmp/ab9e7b971eddb3f10b00175c2fe79daa]: remote 'origin' does not exist","context":{"kind":"Function","name":"github-func","namespace":"test-serverless-gitauth-03h10m00s","version":1}}
{"level":"ERROR","timestamp":"2023-05-18T03:10:31Z","logger":"controllers.function","caller":"serverless/fsm.go:211","message":"while fetching the repository: while fetching remote: Certificate while fetching last commit","context":{"kind":"Function","name":"github-func","namespace":"test-serverless-gitauth-03h10m00s","version":1}}

due to faulty callback implementation.