retry hosts received from hostcache even if marked as failed

core/src/main/groovy/com/muwire/core/hostcache/CacheClient.groovy

@@ -140,7 +140,7 @@ class CacheClient {
 		pong.pongs.asList().each { 
 			Destination dest = new Destination(it)
 			if (!session.getMyDestination().equals(dest))
-				eventBus.publish(new HostDiscoveredEvent(destination: dest)) 
+				eventBus.publish(new HostDiscoveredEvent(destination: dest, fromHostcache : true)) 
 		}
 		
 	}

core/src/main/groovy/com/muwire/core/hostcache/HostCache.groovy

@@ -46,8 +46,8 @@ class HostCache extends Service {
 	void onHostDiscoveredEvent(HostDiscoveredEvent e) {
 		if (myself == e.destination)
 			return
-		if (hosts.containsKey(e.destination))
-			return
+		if (hosts.containsKey(e.destination) && !e.fromHostcache)
+                return
 		Host host = new Host(e.destination)
 		if (allowHost(host)) {
 			hosts.put(e.destination, host)

core/src/main/groovy/com/muwire/core/hostcache/HostDiscoveredEvent.groovy

@@ -7,9 +7,10 @@ import net.i2p.data.Destination
 class HostDiscoveredEvent extends Event {
 
 	Destination destination
-	
+    boolean fromHostcache
+    
 	@Override
 	public String toString() {
-		"HostDiscoveredEvent ${super.toString()} destination:${destination.toBase32()}"
+		"HostDiscoveredEvent ${super.toString()} destination:${destination.toBase32()} from hostcache $fromHostcache"
 	}
 }