Fixed an error in validateRequest
Fixed an error in validateRequest

When uploading files greater than 2Mb I found that where 'invalid_flow_request4' was returned, this was due to it concatenating the strings instead of adding them together, fixed with parseInt. Problem solved.
cadam-telpay/flow.js,danmindru/flow.js,codecentric/flow.js,flowjs/flow.js,Karankang007/flow.js,manoj-nama/flowplus,evilaliv3/flow.js,Symplicity/flow.js,jerlinjames/flow.js,SuberFu/flow.js,SuberFu/flow.js,roccivic/flow.js,manoj-nama/flowplus,dshefchik/flow.js,sahat/flow.js,muhghazaliakbar/flow.js,eric-seekas/flow.js,flowjs/flow.js