config: don't ever overwrite LDFLAGS completely
config: don't ever overwrite LDFLAGS completely

GStreamer/cerbero,nirbheek/cerbero,GStreamer/cerbero,nirbheek/cerbero,atsushieno/cerbero,GStreamer/cerbero,atsushieno/cerbero,GStreamer/cerbero,GStreamer/cerbero,atsushieno/cerbero,atsushieno/cerbero,nirbheek/cerbero,nirbheek/cerbero,atsushieno/cerbero