waf: disable-python - align tdb's wscript

waf: disable-python - align tdb's wscript

Drop the configure option for --disable-python as it is now
global in wafsamba.

If samba is set to use a system copy of tdb, and tdb wasn't built
with python support, then the system pytevent will not be found.  If
samba is being built without python support then pytdb is not needed,
so do not bother to try and find it.

Signed-off-by: Ian Stakenvicius <axs@gentoo.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>