resolved: make sure SIGTER/SIGINT actually can be caught and processed

src/resolve/resolved.c

@@ -64,6 +64,8 @@ int main(int argc, char *argv[]) {
         if (r < 0)
                 goto out;
 
+        assert_se(sigprocmask_many(SIG_BLOCK, SIGTERM, SIGINT, -1) == 0);
+
         r = manager_new(&m);
         if (r < 0) {
                 log_error("Could not create manager: %s", strerror(-r));