[dput-ng-maint] Bug#736351: dput-ng: reports suite-mismatch twice

[Ansgar Burchardt]

Package: dput-ng
Version: 1.7
Severity: minor

Trying to upload a package with UNRELEASED in the changelog and
Distribution: experimental in the .changes output the error message
twice (with different formatting):

----
% dput local dune-common_2.3~20140122gf3403b9-1~ab1_amd64.changes
Uploading dune-common using local to local (host: local; directory: /srv/apt/incoming)
running allowed-distribution: check whether a local profile permits uploads to the target distribution
running checksum: verify checksums before uploading
running suite-mismatch: check the target distribution for common errors
Upload is targeting UNRELEASED but the changes will hit experimental
Upload is targeting `UNRELEASED', but the changes will hit `experimental'.
----

The error should only be shown once.

It would be nice if dput-ng also said that there was an error and the
upload was aborted. You (i.e. paultag) could optinally even make it
colorful ;)

Ansgar