'immediate' Observale.interval failure

[kwonoj]

Snippet below (duplication is intended, single execution works fine)

Rx.Observable.interval(0).take(6).subscribe(console.log);
Rx.Observable.interval(0).take(6).subscribe(console.log);

leads into unexpected failure in nexttick scheduler like below.

\NextTickAction.js:39
                _this.scheduler.scheduled = false;
                                          ^
TypeError: Cannot set property 'scheduled' of undefined
    at Immediate._onImmediate (Z:\github\RxJS\dist\cjs\schedulers\NextTickAction.js:39:43)
    at processImmediate [as _immediateCallback] (timers.js:367:17)

Creating issue while try to triage root cause for this.

[trxcllnt]

@kwonoj looks like it's caused by this check. We should move lines 43-46 from within the conditional to below it.

[kwonoj]

Thanks for tips. I'll try to create PR based on suggestion.