Make getMultipleRecipientServiceAddress more robust

to avoid

feature-not-implemented
	at org.jivesoftware.smack.PacketCollector.nextResultOrThrow(PacketCollector.java:182)
	at org.jivesoftware.smack.PacketCollector.nextResultOrThrow(PacketCollector.java:161)
	at org.jivesoftware.smackx.disco.ServiceDiscoveryManager.discoverItems(ServiceDiscoveryManager.java:573)
	at org.jivesoftware.smackx.address.MultipleRecipientManager.getMultipleRecipienServiceAddress(MultipleRecipientManager.java:310)
 	at org.jivesoftware.smackx.address.MultipleRecipientManager.send$7a184d34(MultipleRecipientManager.java:82)

for e.g. Google Apps XMPP services.

This is not to be merged in master/4.1 branch as it already contains a
similar fix.