Exception on setting MSETimeOffset on Period switch

Created by: KarishmaBagga

Hi I applied the fix fixed in issue #285 (closed) by @KozhinM but on period switch with ABR on I see errors on console: Uncaught TypeError: Cannot read property 'MSETimeOffset' of null (tries to access index 2 when availableRepresentations with it are just 2.). If you note, there are 2 reps in first period (video) and 4 in the other. Some mix up when it sets quality 2 meant for 2nd period?

Owing to this the fix works only intermittently.

Thanks