Fix some issues reported by lintian

Fix some issues reported by lintian

• Bump debhelper from old 11 to 12. (package-uses-old-debhelper-compat-version)
• Set debhelper-compat version in Build-Depends. (uses-debhelper-compat-file)
• Set upstream metadata fields: Bug-Database, Bug-Submit, Repository, Repository-Browse. (upstream-metadata-file-is-missing, upstream-metadata-missing-bug-tracking, upstream-metadata-missing-repository)
• Update standards version to 4.2.1, 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 (out-of-date-standards-version)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/charmtimetracker/53074f05-2cbb-4a4d-a42d-908db85990a2.

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/13/41fb3abe6a7fb5342bb27a6f9275a3f0767f04.debug

Files in first set of .debs but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/0c/36021a776790773e6d1ebc2ca384633f4016f5.debug

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

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

• Build-Ids: 0c36021a776790773e6d1ebc2ca384633f4016f5 1341fb3abe6a7fb5342bb27a6f9275a3f0767f04

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