dbus: no need for systemd and nosystemd setups of the service file

We can just merge them.

configure.ac

@@ -268,6 +268,7 @@ data/Makefile
 data/ModemManager.pc
 data/mm-glib.pc
 data/org.freedesktop.ModemManager1.policy.in
+data/org.freedesktop.ModemManager1.service
 include/Makefile
 include/ModemManager-version.h
 build-aux/Makefile

data/Makefile.am

@@ -34,16 +34,7 @@ endif
 # DBus Activation file
 dbusactivationdir = $(datadir)/dbus-1/system-services
 dbusactivation_DATA = org.freedesktop.ModemManager1.service
-dbusactivation_in_files_systemd = org.freedesktop.ModemManager1.service.systemd.in
-dbusactivation_in_files_nosystemd = org.freedesktop.ModemManager1.service.nosystemd.in
-if HAVE_SYSTEMD
-org.freedesktop.ModemManager1.service: org.freedesktop.ModemManager1.service.systemd.in
-	$(edit) $< >$@
-else
-org.freedesktop.ModemManager1.service: org.freedesktop.ModemManager1.service.nosystemd.in
-	$(edit) $< >$@
-endif
-
+dbusactivation_in_files = org.freedesktop.ModemManager1.service.in
 
 # Icon
 icondir=${datadir}/icons/hicolor/22x22/apps

data/org.freedesktop.ModemManager1.service.in

@@ -6,6 +6,6 @@
 
 [D-BUS Service]
 Name=org.freedesktop.ModemManager1
-Exec=/bin/false
+Exec=@sbindir@/ModemManager
 User=root
 SystemdService=dbus-org.freedesktop.ModemManager1.service

data/org.freedesktop.ModemManager1.service.nosystemd.in

@@ -1,4 +0,0 @@
-[D-BUS Service]
-Name=org.freedesktop.ModemManager1
-Exec=@sbindir@/ModemManager
-User=root