lightning-cli: give error message when lightningd produces non-object response.

Nicer than assert() failing without showing the response.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/lightning-cli.c

@@ -140,6 +140,10 @@ int main(int argc, char *argv[])
 		errx(ERROR_TALKING_TO_LIGHTNINGD,
 		     "Malformed response '%s'", resp);
 
+	if (toks->type != JSMN_OBJECT)
+		errx(ERROR_TALKING_TO_LIGHTNINGD,
+		     "Non-object response '%s'", resp);
+
 	result = json_get_member(resp, toks, "result");
 	if (!result)
 		errx(ERROR_TALKING_TO_LIGHTNINGD,