- disable health server if the health listening address:port is empty
- default health listening address:port to the empty string
- Docker default health listening address:port to 127.0.0.1:9999
- Fix#824
- remove bad calculation of "our own" umask
- remove umask "union effect"
- do not touch system umask unless `UMASK` is set
- set system umask only if `UMASK` is set