Miscellaneous fixes to the Fedora service installer script

- typofix, capitalization
- Gitblit ignores GITBLIT_LOG, might be replaced with GITBLIT_LOG_FOLDER later
- Non-packaged systemd units should be placed under /etc/systemd, refer to [Unit Load Path](http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Unit%20Load%20Path)