systemd: do not rely on racy heuristics to determine master PID

This fixes reloads and stops when systemd is unable to guess master process PID
due to a race described in

While we wait for a proper fix is introduced in either nginx or systemd via
Type=forking, the workaround is not to rely on possibly unset variables, but
hardcode the path to PID file instead where we need it.
4 files changed
tree: b1720379d2604c17154458c9ef890fdb3a348b85
  1. .hgtags
  2. alpine/
  4. debian/
  5. rpm/