Remove unused variables in `database.c`

[sgasse]

This is a trivial change removing two unused variables.

Then please check the following list of things we ask for in your pull request:

• [X] Have you signed the Eclipse Contributor Agreement, using the same email address as you used in your commits?
• [ ] Do each of your commits have a "Signed-off-by" line, with the correct email address? Use "git commit -s" to generate this line for you.
• [ ] If you are contributing a new feature, is your work based off the develop branch?
• [ ] If you are contributing a bugfix, is your work based off the fixes branch?
• [ ] Have you added an explanation of what your changes do and why you'd like us to include them?
• [ ] Have you successfully run make test with your changes locally?

---