Fix some issues reported by lintian

Fix some issues reported by lintian

• Trim trailing whitespace. (trailing-whitespace)
• Update standards version to 4.6.2, no changes needed. (out-of-date-standards-version)
• Avoid explicitly specifying -Wl,--as-needed linker flag. (debian-rules-uses-as-needed-linker-flag)

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/90/f8fc79a27f9396fca8901c691730bebe56fbd0.debug

Files in first set of .debs but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/b1/a0d47fc0cc9967ab6981afb7d92d688b944a31.debug

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

No differences were encountered between the control files of package **gparted-common**

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

• Build-Ids: b1a0d47fc0cc9967ab6981afb7d92d688b944a31 90f8fc79a27f9396fca8901c691730bebe56fbd0

You can also view the diffoscope diff (unfiltered).

This merge proposal was created by the Janitor bot, and it will automatically rebase or close this proposal as appropriate when the target branch changes. Any comments you leave here will be read by the Janitor's maintainers.

Build and test logs for this branch can be found at https://janitor.debian.net/run/1bb1a9af-1d15-496e-8702-089fa1109e72.