Fix counts in nightly emails.

Fix nightly so it correctly get "0" futures, instead of "0]" futures for this
summary:

  [Summary: #Successes = 5021 | #Failures = 4 | #Futures = 0]
Merge pull request #832 from thomasvandoren/fix-nightly-counts

Fix counts in nightly emails.

Fix nightly so it correctly get "0" futures, instead of "0]" futures for this
summary:

    [Summary: #Successes = 5021 | #Failures = 4 | #Futures = 0]

r: @lydia-duncan