autogen: Fetch submodules before running automake

Otherwise automake can't find src/libgsystem.

autogen.sh

@@ -14,8 +14,6 @@ fi
 
 mkdir -p m4
 
-autoreconf --force --install --verbose
-
 # Fetch submodules if needed
 if test ! -f src/libgsystem/README;
 then
@@ -24,6 +22,7 @@ then
 fi
 git submodule update
 
+autoreconf --force --install --verbose
 
 cd $olddir
 test -n "$NOCONFIGURE" || "$srcdir/configure" "$@"