modules: reorder SUBDIRS to process . last

We want to fetch the vlc_modules_list from subdirectories but they must
have already processed their files so that we can include our.

Fix this by reordering SUBDIRS so that "." is processed last instead of
first. This way SUBDIRS (like gui/qt) generate their vlc_modules_list
before the parent directory tries to concatenate them.

modules/Makefile.am

@@ -8,7 +8,7 @@ pkglibexec_PROGRAMS =
 EXTRA_DIST =
 CLEANFILES =
 
-SUBDIRS = .
+SUBDIRS =
 TESTS =
 
 dist_noinst_SCRIPTS = module.rc.in
@@ -145,3 +145,4 @@ vlc_modules_list: Makefile
 
 BUILT_SOURCES += vlc_modules_list
 CLEANFILES += vlc_modules_list
+SUBDIRS += .