Fix bug where with paged request offset
Fix bug where with paged request offset

The offset in PagedJSONIterator wasn't correctly being incremented,
potentially leading into an infinite loop of requests.

codyebberson/box-java-sdk,gcurtis/box-java-sdk,itsmanishagarwal/box-java-sdk,sarattall/box-java-sdk,glawson6/box-java-sdk,manywho/box-java-sdk,TLuthra/box-java-sdk,box/box-java-sdk,bgoldman/box-java-sdk