fix ipaccess-config, call missing nanobts initialization

FIXME: We really need to have some libbsc and libmsc initialization
functions that clean up this mess.
diff --git a/openbsc/src/ipaccess/ipaccess-config.c b/openbsc/src/ipaccess/ipaccess-config.c
index 3b2a8bf..7d559b0 100644
--- a/openbsc/src/ipaccess/ipaccess-config.c
+++ b/openbsc/src/ipaccess/ipaccess-config.c
@@ -561,6 +561,7 @@
 	debug_set_all_filter(stderr_target, 1);
 	debug_set_log_level(stderr_target, 0);
 	debug_parse_category_mask(stderr_target, "DNM,0");
+	bts_model_nanobts_init();
 
 	printf("ipaccess-config (C) 2009 by Harald Welte\n");
 	printf("This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY\n\n");