installation: fix apache configuration
- Creates create "run" directory in instance folder.
- Fixes wrong variable name causing demosite population to fail.
- Adds missing module qrcode to requirements.
- Fixes error output during demosite population.
Co-authored-by: Adrian-Tudor Panescu <adrian.tudor.panescu@cern.ch>
NOTE: beware, patch amended by Tibor to use new file names