Check SslContextFactory, not SSLContext property

References #297

Author: acogoluegnes

src/main/java/com/rabbitmq/client/ConnectionFactory.java

@@ -230,8 +230,8 @@ public void setUri(URI uri)
             // nothing special to do
         } else if ("amqps".equals(uri.getScheme().toLowerCase())) {
             setPort(DEFAULT_AMQP_OVER_SSL_PORT);
-            // SSL context not set yet, we use the default one
-            if (this.sslContext == null) {
+            // SSL context factory not set yet, we use the default one
+            if (this.sslContextFactory == null) {
                 useSslProtocol();
             }
         } else {