Fix some issues reported by lintian

Fix some issues reported by lintian

• Upgrade to newer source format. (older-source-format)
• Update standards version to 4.4.1, no changes needed. (out-of-date-standards-version)
• Add missing colon in closes line. (possible-missing-colon-in-closes)

This merge proposal was created automatically by the Janitor bot.

You can follow up to this merge proposal as you normally would.

Build and test logs for this branch can be found at https://janitor.debian.net/lintian-fixes/pkg/tuxtype/24f97bef-7e16-4ec1-98e2-2f4e89ef45e8.

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 .changes but not in first

-rw-r--r--  root/root   /usr/lib/debug/.build-id/c8/34ae0bc9604682b13799ec342bcfa0823061bd.debug

Files in first .changes but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/e5/d08312041df048641b537cd6ab7bd3a7c123dc.debug

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

No differences were encountered between the control files of package **tuxtype-data**

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

• Build-Ids: e5d08312041df048641b537cd6ab7bd3a7c123dc c834ae0bc9604682b13799ec342bcfa0823061bd

You can also view the diffoscope diff (unfiltered).