do not to unverified if already in verified

host-cache/src/main/groovy/com/muwire/hostcache/HostPool.groovy

@@ -26,7 +26,9 @@ class HostPool {
     }
     
     synchronized def addUnverified(host) {
-        unverified.add(host)
+        if (!verified.contains(host)) {
+            unverified.add(host)
+        }
     }
     
     synchronized def getUnverified(int max) {

host-cache/src/test/groovy/com/muwire/hostcache/HostPoolTest.groovy

@@ -160,4 +160,14 @@ class HostPoolTest {
         assert hp.getVerified(10,true).isEmpty()
         assert hp.getUnverified(10).size() == 1
     }
+    
+    @Test
+    void doNotAddIfVerified() {
+        hp.addUnverified(freeBoth)
+        hp.verify(freeBoth)
+        assert hp.getUnverified(1).isEmpty()
+        
+        hp.addUnverified(freeBoth)
+        assert hp.getUnverified(1).isEmpty()
+    }
 }