Updates submodules file to include latest version of ffpb-debug.

modules

@@ -1,4 +1,4 @@
 GLUON_SITE_FEEDS='ffpb'
 
 PACKAGES_FFPB_REPO=http://git.c3pb.de/freifunk-pb/ffpb-packages.git
-PACKAGES_FFPB_COMMIT=cb21f9c295cf5713c37df4a4cc61fde11fe4f53c
+PACKAGES_FFPB_COMMIT=47477578eebc2e36e71af4f81e581f3660837ce0