Avoid a TypeError when fixing the timestamp
Avoid a TypeError when fixing the timestamp

reviewed by: Julien Le Goff

Sometimes the first timestamp is lower than start value specified by the
newsegment. This can be due to the time scale some muxers use. For now
we set the timestamp to 0 to avoid the component crashing.

flumotion-mirror/flumotion,Flumotion/flumotion,Flumotion/flumotion,Flumotion/flumotion,Flumotion/flumotion,timvideos/flumotion,timvideos/flumotion,flumotion-mirror/flumotion,timvideos/flumotion