Update documentation references in systemd unit files

The systemd unit files for both client and server were referencing
outdated documentation as they were hard-coded to the OpenVPN 2.4.x
release branch.

Github: closes #457

Change-Id: Iee289aa5df9ee0e9a03c0dc562e45dd39836e794
Signed-off-by: Christoph Schug <[email protected]>
Acked-by: Frank Lichtenheld <[email protected]>
Message-Id: <[email protected]>
URL: https://www.mail-archive.com/[email protected]/msg28369.html
Signed-off-by: Gert Doering <[email protected]>

distro/systemd/Makefile.am

@@ -9,7 +9,10 @@
 #
 
 %.service: %.service.in Makefile
-	$(AM_V_GEN)sed -e 's|\@sbindir\@|$(sbindir)|' \
+	$(AM_V_GEN)sed \
+		-e 's|\@OPENVPN_VERSION_MAJOR\@|$(OPENVPN_VERSION_MAJOR)|g' \
+		-e 's|\@OPENVPN_VERSION_MINOR\@|$(OPENVPN_VERSION_MINOR)|g' \
+		-e 's|\@sbindir\@|$(sbindir)|g' \
 		$< > $@.tmp && mv $@.tmp $@
 
 EXTRA_DIST = \

distro/systemd/openvpn-client@.service.in

@@ -3,7 +3,7 @@ Description=OpenVPN tunnel for %I
 After=network-online.target
 Wants=network-online.target
 Documentation=man:openvpn(8)
-Documentation=https://community.openvpn.net/openvpn/wiki/Openvpn24ManPage
+Documentation=https://openvpn.net/community-resources/reference-manual-for-openvpn-@OPENVPN_VERSION_MAJOR@-@OPENVPN_VERSION_MINOR@/
 Documentation=https://community.openvpn.net/openvpn/wiki/HOWTO
 
 [Service]

distro/systemd/openvpn-server@.service.in

@@ -3,7 +3,7 @@ Description=OpenVPN service for %I
 After=network-online.target
 Wants=network-online.target
 Documentation=man:openvpn(8)
-Documentation=https://community.openvpn.net/openvpn/wiki/Openvpn24ManPage
+Documentation=https://openvpn.net/community-resources/reference-manual-for-openvpn-@OPENVPN_VERSION_MAJOR@-@OPENVPN_VERSION_MINOR@/
 Documentation=https://community.openvpn.net/openvpn/wiki/HOWTO
 
 [Service]