It looks like at some point the RAX bind output changed format
slightly, which messed up our backup script. Rework it to parse the
current output.
This parsing is obviously a little fragile ... it is nice to have the
output sorted and lined up nicely (like our manually maintained
opendev.org bind files...). If the format changes again and this
becomes a problem, maybe we switch to dumping the RAX output directly
and forget about formatting it nicely.
Change-Id: I742dd6ef9ffdb377274b384b847625c98dd5ff16
7146cdebaf