[BUG] Null pointer in AkamaiFastPurge.java

[matteobaccan]

Describe the bug

There is a null reference inside invalidateUrls() when status is not assigned

To Reproduce

To reproduce the error is necessary to have a problem with akamai post. After this this line produce a null pointer

return status.toString();

Expected behaviour

Check null pointer

Additional context

I have already fixed the problem and I can submit a FIX