HTTP client pool caches dns lookup forever
When the DefaultHttpClient creates it's poolMap instance a DNS lookup is made and stored in the bootstrap instance:
`                        Bootstrap newBootstrap = bootstrap.clone(group);
                        newBootstrap.remoteAddress(key.getRemoteAddress());
`
The remoteAddress is never updated, which means that if the ip is recycled (very common for AWS hosted services), the pool will continue to try to create connections to the original ip.

### Task List
- [x] Steps to reproduce provided
- [x] Stacktrace (if present) provided
- [x] Example that reproduces the problem uploaded to Github
- [x] Full description of the issue provided (see below)

### Steps to Reproduce
https://github.com/luckyswede/micronaut-dnstest

### Expected Behaviour
When new connections are created a new DNS lookup should take place

### Actual Behaviour
The original DNS lookup result is reused

### Environment Information

- **Operating System**: All
- **Micronaut Version:** 1.2.2
- **JDK Version:** 11

### Example Application
https://github.com/luckyswede/micronaut-dnstest

diff --git a/http-client/src/main/java/io/micronaut/http/client/DefaultHttpClient.java b/http-client/src/main/java/io/micronaut/http/client/DefaultHttpClient.java
index f46d23daad..760d142124 100644
--- a/http-client/src/main/java/io/micronaut/http/client/DefaultHttpClient.java
+++ b/http-client/src/main/java/io/micronaut/http/client/DefaultHttpClient.java
@@ -260,7 +260,6 @@ public class DefaultHttpClient implements RxWebSocketClient, RxHttpClient, RxStr
                         Bootstrap newBootstrap = bootstrap.clone(group);
                         newBootstrap.remoteAddress(key.getRemoteAddress());
 
-
                         AbstractChannelPoolHandler channelPoolHandler = newPoolHandler(key);
                         final Long acquireTimeoutMillis = connectionPoolConfiguration.getAcquireTimeout().map(Duration::toMillis).orElse(-1L);
                         return new FixedChannelPool(
@@ -281,6 +280,7 @@ public class DefaultHttpClient implements RxWebSocketClient, RxHttpClient, RxStr
                     protected ChannelPool newPool(RequestKey key) {
                         Bootstrap newBootstrap = bootstrap.clone(group);
                         newBootstrap.remoteAddress(key.getRemoteAddress());
+
                         AbstractChannelPoolHandler channelPoolHandler = newPoolHandler(key);
                         return new SimpleChannelPool(
                                 newBootstrap,
@@ -2303,7 +2303,7 @@ public class DefaultHttpClient implements RxWebSocketClient, RxHttpClient, RxStr
         }
 
         public InetSocketAddress getRemoteAddress() {
-            return new InetSocketAddress(host, port);
+            return InetSocketAddress.createUnresolved(host, port);
         }
 
         public boolean isSecure() {
['http-client/src/main/java/io/micronaut/http/client/DefaultHttpClient.java']