fixed users serialization
if body content is empty (in case of GET), the isMaxExceeded() method returns true :\
link your engine... wroooommmm
fixed https://github.com/baasbox/baasbox/issues/561 #561
Prevents NPE when 'fields' are specified in query but no 'in' or 'out' fields are returned
Merge branch 'master'# Please enter a commit message to explain why this merge is necessary,