Remove unused import

Change-Id: I222130bb00877a0b043fa5c9d422241e244ca951
diff --git a/admin/warm-cache-1.0.groovy b/admin/warm-cache-1.0.groovy
index 3b1d0ce..02adccb 100644
--- a/admin/warm-cache-1.0.groovy
+++ b/admin/warm-cache-1.0.groovy
@@ -20,7 +20,6 @@
 import com.google.gerrit.server.account.*
 import com.google.gerrit.server.IdentifiedUser
 import com.google.inject.*
-import org.kohsuke.args4j.*
 
 abstract class BaseSshCommand extends SshCommand {