.gitignore: ignore /security/

Change-Id: I4492f85206a3cfe7eebce33ade5a8d89951ad6cb
Signed-off-by: Alexander Martinz <amartinz@shiftphones.com>
diff --git a/.gitignore b/.gitignore
index e29f9d5..05735cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /private/
 /proprietary/
+/security/