stunnel: create PID directory before alt_config_file return

stunnel: create PID directory before alt_config_file return

When alt_config_file is set, global_defs() returns before creating
the PID file directory. stunnel then fails to start because it
cannot write its PID file to the nonexistent directory.

Move the PID directory creation and ownership setup above the
alt_config_file early return so it runs regardless of config mode.

Fixes: openwrt/openwrt#28982
Signed-off-by: Joshua Klinesmith <redacted>
Co-Authored-By: Claude Opus 4.6 (1M context) <redacted>