Set upstream metadata fields: Bug-Submit, Repository, Repository-Browse.

Changes-By: lintian-brush
Fixes: lintian: upstream-metadata-missing-bug-tracking
See-also: https://lintian.debian.org/tags/upstream-metadata-missing-bug-tracking.html
Fixes: lintian: upstream-metadata-missing-repository
See-also: https://lintian.debian.org/tags/upstream-metadata-missing-repository.html

debian/upstream/metadata

 ASCL-Id: 1208.001
 Bug-Database: https://github.com/dstndstn/astrometry.net/issues
 Name: astrometry.net
+Bug-Submit: https://github.com/dstndstn/astrometry.net/issues/new
 Reference:
  Author: Lang, D. and Hogg, D. W. and Mierle, K. and Blanton, M. and Roweis, S.
  Doi: 10.1088/0004-6256/139/5/1782
@@ -11,5 +12,6 @@ Reference:
  URL: https://adsabs.harvard.edu/abs/2010AJ....139.1782L
  Volume: 139
  Year: 2010
-Repository: https://github.com/dstndstn/astrometry.net
+Repository: https://github.com/dstndstn/astrometry.net.git
+Repository-Browse: https://github.com/dstndstn/astrometry.net
 Webservice: http://nova.astrometry.net/