Revert "Keep support for legacy S3 client"

This reverts commit 7a54156.

Author: tomas-sexenian

gxcloudstorage-awss3/pom.xml

@@ -29,10 +29,5 @@
             <artifactId>s3</artifactId>
             <version>${software.awssdk.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.amazonaws</groupId>
-            <artifactId>aws-java-sdk-s3</artifactId>
-            <version>1.12.587</version>
-        </dependency>
     </dependencies>
 </project>