build: generate man/NetworkManager.conf.xml by autoconf

Signed-off-by: Thomas Haller <thaller@redhat.com>

.gitignore

@@ -205,6 +205,7 @@ valgrind-*.log
 /m4/xsize.m4
 
 /man/*.[185]
+/man/NetworkManager.conf.xml
 /man/nm-settings.xml
 /man/nm-settings-ifcfg-rh.xml
 /man/nm-settings-keyfile.xml

configure.ac

@@ -918,6 +918,7 @@ initscript/linexa/networkmanager
 introspection/Makefile
 introspection/all.xml
 man/Makefile
+man/NetworkManager.conf.xml
 man/nm-system-settings.conf.5
 man/nm-online.1
 man/nmcli.1