handler: reduce cyclomatic complexity of query deserialization
handler: reduce cyclomatic complexity of query deserialization

SkygearIO/skygear-server,SkygearIO/skygear-server,SkygearIO/skygear-server,rickmak/skygear-server,SkygearIO/skygear-server,rickmak/skygear-server,rickmak/skygear-server