Print proper name in show-queue for cache eviction

Change-Id: I350d08dd3ffb9a146b077d68c0710c44c1c72454

src/main/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheHandler.java

diff --git a/src/main/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheHandler.java b/src/main/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheHandler.java
index ecd2a9b..fe8dc3a 100644
--- a/src/main/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheHandler.java
+++ b/src/main/java/com/ericsson/gerrit/plugins/evictcache/EvictCacheHandler.java
@@ -64,5 +64,11 @@
     public void run() {
       restSession.evict(pluginName, cacheName, key);
     }
+
+    @Override
+    public String toString() {
+      return String.format("Evict key '%s' from cache '%s' in target instance",
+          key, cacheName);
+    }
   }
 }