fix: adapted example

Author: dervoeti

docs/modules/hdfs/examples/getting_started/webhdfs.yaml

@@ -18,6 +18,6 @@ spec:
     spec:
       containers:
         - name: webhdfs
-          image: oci.stackable.tech/sdp/testing-tools:0.2.0-stackable0.0.0-dev
+          image: oci.stackable.tech/sdp/testing-tools:0.3.0-stackable0.0.0-dev
           stdin: true
           tty: true