Fix some issues reported by lintian

Fix some issues reported by lintian

• Update standards version to 4.4.1, no changes needed. (out-of-date-standards-version)
• Bump debhelper from old 11 to 12. (package-uses-old-debhelper-compat-version)
• Set debhelper-compat version in Build-Depends. (uses-debhelper-compat-file)

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/kdevelop-pg-qt/43a70a93-7f9a-4141-81a3-349bc3d45262.

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/02/5a6c4937f5655b77bc7936af49d0b37941547f.debug

Files in first .changes but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/43/2e64bf2bb652e4bb44c0aafa6177c01e815433.debug

No differences were encountered between the control files of package **kdevelop-pg-qt**

Control files of package kdevelop-pg-qt-dbgsym: lines which differ (wdiff format)

• Build-Ids: 432e64bf2bb652e4bb44c0aafa6177c01e815433 025a6c4937f5655b77bc7936af49d0b37941547f

You can also view the diffoscope diff (unfiltered).