Remove "Host" header in Aws API calls

HttpClient in J11 will raise  `java.lang.IllegalArgumentException: restricted header name: "Host"` if a "Host" header is provided - there are overrides for this in J12 onwards, but not possible in J11.

hazelcast/src/main/java/com/hazelcast/aws/AwsEc2Api.java

@@ -232,7 +232,8 @@ private Map<String, String> createHeaders(Map<String, String> attributes, AwsCre
         if (!StringUtil.isNullOrEmptyAfterTrim(credentials.getToken())) {
             headers.put("X-Amz-Security-Token", credentials.getToken());
         }
-        headers.put("Host", endpoint);
+        // "Host" header is restricted with HttpClient in J11 - when we send our request,
+        //  it is automatically set to the URL host (which in this case is `endpoint` still)
         String timestamp = currentTimestamp(clock);
         headers.put("X-Amz-Date", timestamp);
         headers.put("Authorization", requestSigner.authHeader(attributes, headers, "", credentials, timestamp, "GET"));

hazelcast/src/main/java/com/hazelcast/aws/AwsEcsApi.java

@@ -154,7 +154,8 @@ private Map<String, String> createHeaders(String body, AwsCredentials credential
         if (!StringUtil.isNullOrEmptyAfterTrim(credentials.getToken())) {
             headers.put("X-Amz-Security-Token", credentials.getToken());
         }
-        headers.put("Host", endpoint);
+        // "Host" header is restricted with HttpClient in J11 - when we send our request,
+        //  it is automatically set to the URL host (which in this case is `endpoint` still)
         headers.put("X-Amz-Target", String.format("AmazonEC2ContainerServiceV20141113.%s", awsTargetAction));
         headers.put("Content-Type", "application/x-amz-json-1.1");
         headers.put("Accept-Encoding", "identity");