bankd: Don't consume 100% CPU in main thread

Change-Id: I4586a4c00fcdd4540f84caa005d2f116a63aa59c
diff --git a/src/bankd_main.c b/src/bankd_main.c
index fe96186..491958f 100644
--- a/src/bankd_main.c
+++ b/src/bankd_main.c
@@ -92,6 +92,7 @@
 	while (1) {
 		if (terminate)
 			break;
+		sleep(1);
 	}
 
 	talloc_free(bankd);