Fix some issues reported by lintian

Fix some issues reported by lintian

• Trim trailing whitespace. (file-contains-trailing-whitespace)
• Set upstream metadata fields: Bug-Database, Repository, Repository-Browse. (upstream-metadata-file-is-missing)
• Update standards version to 4.4.1, no changes needed. (out-of-date-standards-version)
• Set upstream metadata fields: Bug-Submit. (upstream-metadata-missing-bug-tracking)
• Refer to specific version of license GPL-2+. (copyright-refers-to-symlink-license, copyright-refers-to-versionless-license-file)
• Update standards version to 4.5.0, no changes needed. (out-of-date-standards-version)

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/light-locker/a2d0ef5b-f871-48c7-b9aa-eed19ac8bfba.

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/e6/d7b2b51ce68cf8d3bf00891b59627acdedb9ab.debug

Files in first set of .debs but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/b7/8737e11c8d905cf66f82cdc5fb92a83295902c.debug

No differences were encountered between the control files of package **light-locker**

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

• Build-Ids: b78737e11c8d905cf66f82cdc5fb92a83295902c e6d7b2b51ce68cf8d3bf00891b59627acdedb9ab ef8d9220f55b8819e33bac9bf8248d9502b764b1

You can also view the diffoscope diff (unfiltered).