Gracefully handle exceptions in httpclient callback to avoid hanging (#1615)

Author: jonasasx

api/src/main/java/io/minio/S3Base.java

@@ -615,6 +615,14 @@ public void onFailure(final Call call, IOException e) {
 
               @Override
               public void onResponse(Call call, final Response response) throws IOException {
+                try {
+                  onResponse(response);
+                } catch (Exception e) {
+                  completableFuture.completeExceptionally(e);
+                }
+              }
+
+              private void onResponse(final Response response) throws IOException {
                 String trace =
                     response.protocol().toString().toUpperCase(Locale.US)
                         + " "