Remove unused imports

Author: slandelle

client/src/main/java/org/asynchttpclient/netty/channel/ChannelManager.java

@@ -43,15 +43,12 @@
 import java.net.InetSocketAddress;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Optional;
-import java.util.OptionalLong;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import javax.net.ssl.SSLEngine;
 import javax.net.ssl.SSLException;