gitignore: add gen_sabp.stamp

Change-Id: I107d2c0e8c82523a8fb38f128bb81e32e437bdd8
diff --git a/.gitignore b/.gitignore
index 49b2cfb..e32000c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,6 +39,7 @@
 gen_hnbap.stamp
 gen_rua.stamp
 gen_ranap.stamp
+gen_sabp.stamp
 include/osmocom/hnbap/hnbap_ies_defs.h
 include/osmocom/rua/rua_ies_defs.h
 include/osmocom/ranap/ranap_ies_defs.h