daemon: don't re-exec if the linker supports the -z,now option

daemon: don't re-exec if the linker supports the -z,now option

Usually PulseAudio is built with a linker that supports the -z,now
option, and that option should have the same effect (i.e. the dynamic
linker resolves all symbols when the program is started) as re-execing
with the LD_BIND_NOW environment variable set, so usually the re-execing
is redundant.

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=104789