Core Update 173: Ship libconfig

Note to self: Does the filesystem cleanup routine called in update.sh
handle the rootfile changes of this properly?

Signed-off-by: Peter Müller <peter.mueller@ipfire.org>

diff --git a/config/rootfiles/core/173/filelists/libconfig b/config/rootfiles/core/173/filelists/libconfig
new file mode 120000 (symlink)
index 0000000..6e4e067
--- /dev/null
+++ b/config/rootfiles/core/173/filelists/libconfig
@@ -0,0 +1 @@
+../../../common/libconfig
\ No newline at end of file