chore(package.json): correct RxJS 4 dependency
chore(package.json): correct RxJS 4 dependency

figueredo/RxJS,gluck/RxJS,ReactiveX/rxjs,Igorbek/rxjs5,ReactiveX/rxjs,Igorbek/rxjs5,ReactiveX/rxjs,adrianomelo/RxJS-1,kwonoj/RxJS,RxJS-CN/RxJS-Docs-CN,kwonoj/RxJS,SangKa/RxJS-Docs-CN,SangKa/RxJS-Docs-CN,jayphelps/rxjs,adrianomelo/RxJSNext,SangKa/RxJS-Docs-CN,Igorbek/rxjs5,martinsik/rxjs,martinsik/rxjs,elliotschi/rxjs,benlesh/RxJS,jayphelps/rxjs,trxcllnt/RxJS,Igorbek/rxjs5,elliotschi/rxjs,benlesh/RxJS,saneyuki/RxJS,robwormald/RxJS,figueredo/RxJS,jayphelps/rxjs,trxcllnt/RxJS,adrianomelo/RxJSNext,Brocco/RxJS,robwormald/RxJS,kwonoj/RxJS,staltz/RxJSNext,adrianomelo/RxJS-1,staltz/RxJSNext,ReactiveX/RxJS,saneyuki/RxJS,ReactiveX/RxJS,RxJS-CN/RxJS-Docs-CN,adrianomelo/RxJSNext,martinsik/rxjs,ReactiveX/rxjs,adrianomelo/RxJSNext,RxJS-CN/RxJS-Docs-CN,benlesh/RxJS,benlesh/RxJS,IgorMinar/RxJS,Brocco/RxJS,gluck/RxJS,elliotschi/rxjs,staltz/RxJSNext,robwormald/RxJS,adrianomelo/RxJS-1,trxcllnt/RxJS,staltz/RxJSNext,gluck/RxJS,kwonoj/RxJS,IgorMinar/RxJS,RxJS-CN/RxJS-Docs-CN,ReactiveX/RxJS,Brocco/RxJS,jayphelps/rxjs,figueredo/RxJS,adrianomelo/RxJS-1,robwormald/RxJS,gluck/RxJS,martinsik/rxjs,elliotschi/rxjs,jayphelps/rxjs,SangKa/RxJS-Docs-CN,trxcllnt/RxJS,figueredo/RxJS,Brocco/RxJS,ReactiveX/RxJS