RFR: Properly check for user not found in Jira

[Robin Westberg]

When checking if a user can be found by email address, the result will be an array on success, and something else
otherwise.

Best regards,
Robin

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Commit messages:
 - Properly check for user not found

Changes: https://git.openjdk.java.net/skara/pull/808/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=808&range=00
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/808.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/808/head:pull/808

PR: https://git.openjdk.java.net/skara/pull/808