Trim trailing whitespace.

Changes-By: lintian-brush
Fixes: lintian: trailing-whitespace
See-also: https://lintian.debian.org/tags/trailing-whitespace.html

debian/control

@@ -10,4 +10,3 @@ Architecture: any
 Depends: ${shlibs:Depends}, ${misc:Depends}
 Description: Apache2 Prometheus exporter.
  Exports Prometheus metrics from an Apache2 instance.
-

debian/rules

@@ -10,4 +10,3 @@ export DH_GOLANG_EXCLUDES = vendor
 override_dh_install:
 	rm -fr $(CURDIR)/debian/apache-exporter/usr/share/gocode
 	dh_install
-