daemon: only call pw_log_set_level() if -v is actually given
Previous commit 69e935e8 unconditionally called pw_log_set_level() after the option parsing. If pw_init() changed the logging level based on PIPEWIRE_DEBUG, we'd now overwrite that change.
Call pw_log_set_level() only if -v is actually given on the commandline. This means a commandline option will override PIPEWIRE_DEBUG if set but that is intended.
Fixes 69e935e8