Bump debhelper from deprecated 9 to 12.

Changes-By: lintian-brush
Fixes: lintian: package-uses-deprecated-debhelper-compat-version
See-also: https://lintian.debian.org/tags/package-uses-deprecated-debhelper-compat-version.html

debian/compat

-9
+12

debian/control

@@ -2,7 +2,7 @@ Source: cgroups-exporter
 Section: admin
 Priority: optional
 Maintainer: ale <ale@incal.net>
-Build-Depends: debhelper (>= 9.20160709), dh-golang, golang-any
+Build-Depends: debhelper (>= 12~), dh-golang, golang-any
 Standards-Version: 3.9.5
 
 Package: cgroups-exporter

debian/rules

@@ -5,7 +5,7 @@ export DH_GOPKG := git.autistici.org/ai3/tools/cgroups-exporter
 export DH_GOLANG_EXCLUDES := vendor
 
 %:
-	dh $@ --buildsystem=golang --with=golang --with=systemd
+	dh $@ --buildsystem=golang --with=golang
 
 override_dh_auto_install:
 	dh_auto_install