Add hidden default constructor to ConnectionConfiguration

aSmack subclasses ConnectionConfiguration and needs a constructor that
does no network I/O.

source/org/jivesoftware/smack/ConnectionConfiguration.java

@@ -94,6 +94,13 @@ public class ConnectionConfiguration implements Cloneable {
 	// Holds the proxy information (such as proxyhost, proxyport, username, password etc)
     protected ProxyInfo proxy;
 
+    /**
+     * Constructor used for subclassing ConnectionConfiguration
+     */
+    ConnectionConfiguration() {
+      /* Does nothing */
+    }
+
     /**
      * Creates a new ConnectionConfiguration for the specified service name.
      * A DNS SRV lookup will be performed to find out the actual host address