core172: add missing armv6 rootfile link for python3

this fix build of core172 for armv6.

Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>

diff --git a/config/rootfiles/core/172/filelists/armv6l/python3 b/config/rootfiles/core/172/filelists/armv6l/python3
new file mode 120000 (symlink)
index 0000000..605f806
--- /dev/null
+++ b/config/rootfiles/core/172/filelists/armv6l/python3
@@ -0,0 +1 @@
+../../../../common/armv6l/python3
\ No newline at end of file