Qingwei/unsubscribe contract (#554)
Qingwei/unsubscribe contract (#554)

* Unsubscribe data when contract ended

* Set shift mode to dynamic for contract chart

binary-com/binary-next-gen,binary-com/binary-next-gen,nazaninreihani/binary-next-gen,nazaninreihani/binary-next-gen,nuruddeensalihu/binary-next-gen,nuruddeensalihu/binary-next-gen,binary-com/binary-next-gen,nazaninreihani/binary-next-gen,nuruddeensalihu/binary-next-gen