Packaging cleanup

* Declare compliance with policy 4.6.2
* Update watch file

debian/control

@@ -1,7 +1,7 @@
 Source: nagios-tang
 Maintainer: Christoph Biedl <debian.axhn@manchmal.in-ulm.de>
 Homepage: https://github.com/latchset/nagios-tang
-Standards-Version: 4.5.1
+Standards-Version: 4.6.2
 Vcs-Browser: https://git.in-ulm.de/cbiedl/nagios-tang
 Vcs-Git: https://git.in-ulm.de/cbiedl/nagios-tang.git
 Build-Depends: debhelper-compat (= 13),

debian/watch

@@ -1,4 +1,5 @@
 
 version=4
-https://github.com/latchset/@PACKAGE@/releases \
+opts="searchmode=plain,filenamemangle=s/$/.tar.gz/" \
+https://api.github.com/repos/latchset/@PACKAGE@/releases \
     /latchset/@PACKAGE@/releases/download/[^/]+/@PACKAGE@-([0-9][.0-9]*)@ARCHIVE_EXT@