[network-manager-applet] build: don't require libnm-glib for make distcheck

[Lubomir Rintel <lkundrak src gnome org>]

commit 3e85cf62828d7491336fc094db1aa5156a8b3b0f
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Mon May 27 19:34:44 2019 +0200

    build: don't require libnm-glib for make distcheck
    
    The library is no more.
    
    https://gitlab.gnome.org/GNOME/network-manager-applet/merge_requests/50

 Makefile.am | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/Makefile.am b/Makefile.am
index 977d640f..c863e8d4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -33,11 +33,15 @@ DISTCHECK_CONFIGURE_FLAGS = \
        --enable-gtk-doc \
        --enable-introspection \
        --enable-more-warnings=error \
-       --with-libnm-gtk \
        --with-wwan \
        --with-team \
        --with-gcr
 
+
+if WITH_LIBNM_GTK
+DISTCHECK_CONFIGURE_FLAGS += --with-libnm-gtk
+endif
+
 man_MANS =
 
 pkgconfig_DATA =