removing ldflags for openbsd

[tridge at samba.org]

Hi Matthieu,

 > -    conf.ADD_LDFLAGS('-Wl,-no-undefined', testflags=True)
 > +    if sys.platform != "openbsd4":
 > +        conf.ADD_LDFLAGS('-Wl,-no-undefined', testflags=True)

It would be better to fix the configure tests to test if the flags
work correctly. If you can work out what actually fails on openbsd
then we could add a test that ensures it works on all platforms.

Cheers, Tridge