Enable multipart upload support (#353)

Author: ScopelyChristianFusco

src/main/java/hudson/plugins/s3/ClientHelper.java

@@ -46,6 +46,7 @@ public static S3AsyncClient createAsyncClient(String accessKey, String secretKey
         Region awsRegion = getRegionFromString(region);
         S3AsyncClientBuilder builder = S3AsyncClient.builder();//.overrideConfiguration(clientConfiguration);
         builder.region(awsRegion);
+        builder.multipartEnabled(true);
 
         if (!useRole) {
             builder = builder.credentialsProvider(() -> AwsBasicCredentials.create(accessKey, secretKey));