CORD-2272: Drop deprecated header.py

Change-Id: I70ff4533ba23b8639a26496e91debe63fceec584
(cherry picked from commit d26f904acf69f54c6c1c5eafe5a0c106484639fb)
diff --git a/xos/header.py b/xos/header.py
deleted file mode 120000
index 721b5c0..0000000
--- a/xos/header.py
+++ /dev/null
@@ -1 +0,0 @@
-attic/header.py
\ No newline at end of file