nat: Fix the test case by allocating a config.
For the statistics we do need to have an allocated config,
otherwise we will nicely crash.
diff --git a/openbsc/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index e547ee4..aabc130 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -242,6 +242,7 @@
fprintf(stderr, "Testing connection tracking.\n");
nat = bsc_nat_alloc();
con = bsc_connection_alloc(nat);
+ con->cfg = bsc_config_alloc(nat, "foo", 23);
msg = msgb_alloc(4096, "test");
/* 1.) create a connection */