wocky-debug.h: fix wocky_debug_set_flags_from_env prototype
wocky-debug.h: fix wocky_debug_set_flags_from_env prototype

noonien-d/wocky,freedesktop-unofficial-mirror/wocky,freedesktop-unofficial-mirror/wocky,freedesktop-unofficial-mirror/wocky,noonien-d/wocky,noonien-d/wocky