Could not get story point when first card's story point is empty

[GRXself]

Issue

Give:
An iteration with several cards. The first card in generated board data excel, its story point is not set. Other cards' story point is set.
Then:
Try to generate this iteration's board data.
Expect:
The first card's story point in generated excel should be empty while other cards' story point should be the exact one.
Actual:
All cards' story point in generate excel is empty.

How to reproduce:

In an iteration, leave the first card's story point unset. Other cards' story point could be set or not set. Then try to generate the board data, all cards' story point will be empty.

Note

The order will be changed if we try to fill the first card's story point. That means if we set the story point after we found the issue, when we regenerate the data, the first card could be different.

[GRXself]

##Update
Even when the first card in the generated data has story point, there is no story point in the generated data.