Fix batch fetch result on error

[felipenr]

Maybe fix some issues for who uses "apollo-link-batch-http"

• errorPolicy ('ignore' and 'all') doesn't work in case of network error apollo-client#3034
• Right way to handle ApolloErrors react-apollo#1318
• errorPolicy not working react-apollo#1389

Problem:

Apollo client does not returns "data" values when has error on fetch. Even if I set errorPolicy 'all' or 'ignore'.

Cause:

"apollo-link-batch-http" returns Array result on fetch and not a Object.

Solution:

Fix condition to returns data on fetch error.

[apollo-cla]

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