[libglnx/mwleeds/fix-config-h-clean] Add libglnx-config.h to CLEANFILES

[Phaedrus Leeds <mwleeds src gnome org>]

commit b73a467a97688ba4fde002fb69be159c160e4234
Author: Phaedrus Leeds <mwleeds protonmail com>
Date:   Tue Mar 1 11:51:44 2022 -0800

    Add libglnx-config.h to CLEANFILES
    
    This fixes make distcheck for Flatpak (but you have to re-run
    autogen.sh).

 Makefile-libglnx.am | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/Makefile-libglnx.am b/Makefile-libglnx.am
index 9d1faa9..bea7b13 100644
--- a/Makefile-libglnx.am
+++ b/Makefile-libglnx.am
@@ -25,6 +25,7 @@ EXTRA_DIST += \
        $(NULL)
 
 BUILT_SOURCES += $(top_builddir)/libglnx-config.h
+CLEANFILES += $(top_builddir)/libglnx-config.h
 $(top_builddir)/libglnx-config.h: Makefile.am
        echo '#include "config.h"' > $@