List of fixes:
- Do not fail to add the user 'gogs' to the group 'www-data',
  explicitely creates it first.
- Explicitely pass the path to the .ini file to the gogs binary.
- Use openrc-run instead of runscript.
- Patch the list.tmpl template not to cause a fatal error when gogs
  starts.

Now all invocations have following order of arguments (if present):

    addgroup -S -g ... GROUP
    adduser -S -u ... -D -H -h ... -s ... -G ... -g ... USER

Following rules have been applied:
- script starts with shebang !#/bin/sh followed by blank line,
- script ends with exit 0 prepended by blank line,
- only stderr of adduser, addgroup or passwd is redirected to /dev/null,
- getent passwd/group instances has been removed,
- manual checking of file and group existence has been removed,
- `|| true` instances has been removed.

Comments and line wrapping have been preserved.

This way we can avoid ugly default:

    Linux user,,,