Fix broken intro point unittest.

The structure was not zeroed out, and left some boolean fields
uninitialized.

src/test/test_hs_service.c

@@ -1092,6 +1092,8 @@ test_build_update_descriptors(void *arg)
     tor_addr_t ipv4_addr;
     curve25519_secret_key_t curve25519_secret_key;
 
+    memset(&ri, 0, sizeof(routerinfo_t));
+
     tor_addr_parse(&ipv4_addr, "127.0.0.1");
     ri.addr = tor_addr_to_ipv4h(&ipv4_addr);
     ri.or_port = 1337;