Simplify dunstify flags

Makefile

@@ -78,6 +78,6 @@ test-clean:
 	rm -f test/test test/*.o
 
 dunstify: dunstify.o
-	${CC} ${CFLAGS} -o $@ dunstify.o $(shell pkg-config --libs --cflags glib-2.0 libnotify gdk-3.0)
+	${CC} ${CFLAGS} -o $@ dunstify.o ${LDFLAGS}
 
 .PHONY: all clean dist install uninstall

config.mk

@@ -32,6 +32,11 @@ else
 $(warning STATIC_CONFIG is deprecated behavior. It will get removed in future releases)
 endif
 
+# dunstify also needs libnotify
+ifneq (,$(findstring dunstify,${MAKECMDGOALS}))
+	pkg_config_packs += libnotify
+endif
+
 # includes and libs
 INCS := $(shell ${PKG_CONFIG} --cflags ${pkg_config_packs})
 CFLAGS += ${INCS}