Remove hard-coded 127.0.0.1 loopback address

This bug is a continuation of JDK-8220083

Some of the JDK networking tests hard-code as the 127.0.0.1 loopback address. This works on IPv4 or IPv6&IPv4 network. However, with IPv6-only network, those tests with hard-coded address fail. The following fix would work for IPv4, IPv6&IPv4, and IPv6-only environment:

- so = new Socket("127.0.0.1", port);
+ so = new Socket(InetAddress.getLoopbackAddress(), port);

The following tests are still affected:

* jdk/javax/net/ssl/TLS/TestJSSE.java
* jdk/javax/net/ssl/sanity/interop/JSSEClient.java