camlimages_2.12-6 should be put in Needs-Build on hppa

[Julien Cristau <julien.cristau@ens-lyon.fr>]

Hello hppa buildd maintainers,

according to http://www.buildd.net/buildd/hppa_Dep-Wait.html, it seems 
that camlimages should be manually put from Dep-Wait to Needs-Build:
it is currently waiting for the nonexistent package "rpath", which is a 
spurious build-dep and has been removed from the control file in 
camlimages_2.12-5. 
camlimages is part of the tiff4 transition as well as the ocaml new 
version.
Thanks in advance.

Regards,
Julien Cristau