Fix some issues reported by lintian

Fix some issues reported by lintian

• Trim trailing whitespace. (file-contains-trailing-whitespace)
• Use secure copyright file specification URI. (insecure-copyright-format-uri)
• Bump debhelper from old 11 to 12. (package-uses-old-debhelper-compat-version)
• debian/copyright: use spaces rather than tabs to start continuation lines. (tab-in-licence-text)
• Fix field name typos in debian/copyright. (field-name-typo-dep5-copyright)
• Update standards version to 4.4.1, 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 (out-of-date-standards-version)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/xfce4-sensors-plugin/feb9987f-88dd-4391-a02b-31d596a8b130.

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/b9/c033b0197a332cce86e615e94eae37c60afa48.debug
-rw-r--r--  root/root   /usr/lib/debug/.build-id/cf/708a5630e826107e330360f2baf42e0ac2078a.debug
-rw-r--r--  root/root   /usr/lib/debug/.build-id/e4/00e07171d1b8cbab8500923b6a8c8232a1305a.debug
-rw-r--r--  root/root   /usr/lib/debug/.dwz/x86_64-linux-gnu/xfce4-sensors-plugin.debug

Files in first .changes but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/19/a1814ede0afd3cc4ba07f072d3ddfd3cae3ff3.debug
-rw-r--r--  root/root   /usr/lib/debug/.build-id/57/4d2a361f74a6892c3964ea5b239d1eb7b3537d.debug
-rw-r--r--  root/root   /usr/lib/debug/.build-id/7d/50ad5200ae1aba1e4056753241296233789b9b.debug

No differences were encountered between the control files of package **xfce4-sensors-plugin**

Control files of package xfce4-sensors-plugin-dbgsym: lines which differ (wdiff format)

• Build-Ids: 19a1814ede0afd3cc4ba07f072d3ddfd3cae3ff3 574d2a361f74a6892c3964ea5b239d1eb7b3537d 7d50ad5200ae1aba1e4056753241296233789b9b b9c033b0197a332cce86e615e94eae37c60afa48 cf708a5630e826107e330360f2baf42e0ac2078a e400e07171d1b8cbab8500923b6a8c8232a1305a

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