nat: remove is called on already patched connections..

Fix the test to search for the original message instead
of the already patched one that should not find any items
anyway.

The remove is called on already patched connections so we
need to match it with the patch reference count.
diff --git a/openbsc/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index 705372c..8ec5914 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -290,6 +290,10 @@
 		abort();
 	}
 	remove_sccp_src_ref(con, msg, parsed);
+	talloc_free(parsed);
+
+	copy_to_msg(msg, bsc_rlc, sizeof(bsc_rlc));
+	parsed = bsc_nat_parse(msg);
 	con_found = patch_sccp_src_ref_to_msc(msg, parsed, nat);
 
 	/* verify that it is gone */