Bump soname

Bump soname

Bump once to the stable interface we have now. This isn't really required as
we're compatible with everything but functions deprecated with 0.4 but we
might as well do it now to force a rebuild of everyone. Should've done that
for 0.6 when we actually dropped the function, but ...

Now that we have proper library versioning we shouldn't need any
backwards-incompatible soname bumps for a while.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>