net.resolvers.basic: Fix continuing if IPv6 or Legacy IP is disabled

The code expects ready() to be called twice, but with IPv4 or v6
disabled it would only be called once.

net/resolvers/basic.lua

@@ -52,6 +52,8 @@ function methods:next(cb)
 			end
 			ready();
 		end, self.hostname, "A", "IN");
+	else
+		ready();
 	end
 
 	if not self.extra or self.extra.use_ipv6 ~= false then
@@ -63,6 +65,8 @@ function methods:next(cb)
 			end
 			ready();
 		end, self.hostname, "AAAA", "IN");
+	else
+		ready();
 	end
 end