Fix some issues reported by lintian

Fix some issues reported by lintian

• Trim trailing whitespace. (trailing-whitespace)

• Bump debhelper from old 11 to 13. (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)

This merge proposal was created automatically by the Janitor bot. For more information, including instructions on how to disable these merge proposals, see https://janitor.debian.net/lintian-fixes.

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Build and test logs for this branch can be found at https://janitor.debian.net/lintian-fixes/pkg/smtpping/176fc5dd-e9de-40e6-825b-0c0751841609.

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/4c/b29030a0605600ea0b11cabefe167cd9c481a1.debug

Files in first set of .debs but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/9d/a2950769b6728c443d92ec8ddadd430f31a9a5.debug

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

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

• Build-Ids: 9da2950769b6728c443d92ec8ddadd430f31a9a5 4cb29030a0605600ea0b11cabefe167cd9c481a1

You can also view the diffoscope diff (unfiltered).