Fix some issues reported by lintian

Fix some issues reported by lintian

• Trim trailing whitespace. (trailing-whitespace)
• Use secure copyright file specification URI. (insecure-copyright-format-uri)
• Bump debhelper from old 12 to 13. (package-uses-old-debhelper-compat-version)
• Set upstream metadata fields: Bug-Database, Bug-Submit, Repository-Browse. (upstream-metadata-missing-bug-tracking, upstream-metadata-missing-repository)
• Update standards version to 4.6.2, no changes needed. (out-of-date-standards-version)

Debdiff

These changes affect the binary packages:

[The following lists of changes regard files as different if they have different names, permissions or owners.]

Files in second set of .debs but not in first

-rw-r--r--  root/root   /usr/lib/debug/.build-id/48/27e09f57a1da212f4110c590f0a8995169014e.debug

Files in first set of .debs but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/02/7b43c77af23346835d0484e730afc0d6763c63.debug

No differences were encountered between the control files of package **libmsnumpress-dev**

No differences were encountered between the control files of package **libmsnumpress1**

Control files of package libmsnumpress1-dbgsym: lines which differ (wdiff format)

• Build-Ids: 027b43c77af23346835d0484e730afc0d6763c63 4827e09f57a1da212f4110c590f0a8995169014e

You can also view the diffoscope diff (unfiltered).

This merge proposal was created by the Janitor bot, and it will automatically rebase or close this proposal as appropriate when the target branch changes. Any comments you leave here will be read by the Janitor's maintainers.

Build and test logs for this branch can be found at https://janitor.debian.net/lintian-fixes/pkg/libmsnumpress/a31b4f78-6307-4942-8b81-ca41baab4152.