- If the session doesn't exist, it shouldn't be expected that the
variable is non-nil. Define the session variable instead and insert that.
- Add unit tests to test the behavior of the database sessions code .
- Regression caused by dd30d9d5c0.
- Resolves https://codeberg.org/forgejo/forgejo/issues/2042
(cherry picked from commit 90307ad200)
(cherry picked from commit 874ef1978d)
