[#5313] Correctly catch errors during bootstrap.

Motivation:

We not correctly catched errors during resolving in bootstrap and so may not have notified the future correctly.

Modifications:

Move code into try / catch block and try to fail the promise.

Result:

Promise is always notified

transport/src/main/java/io/netty/bootstrap/Bootstrap.java

@@ -194,6 +194,7 @@ public class Bootstrap extends AbstractBootstrap<Bootstrap, Channel> {
 
     private ChannelFuture doResolveAndConnect0(final Channel channel, SocketAddress remoteAddress,
                                                final SocketAddress localAddress, final ChannelPromise promise) {
+        try {
             final EventLoop eventLoop = channel.eventLoop();
             final AddressResolver<SocketAddress> resolver = this.resolver.getResolver(eventLoop);
 
@@ -231,7 +232,9 @@ public class Bootstrap extends AbstractBootstrap<Bootstrap, Channel> {
                     }
                 }
             });
-
+        } catch (Throwable cause) {
+            promise.tryFailure(cause);
+        }
         return promise;
     }