Fix a bug

[mfeurer]

Fixes a bug which makes sure that uploading a task does not fail due to the task already existing on the test server.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (develop@bed8652). Click here to learn what that means.
The diff coverage is n/a.

@@ Coverage Diff @@## develop #700 +/- ##
==========================================
Coverage ? 90.36% ==========================================
Files ? 36 Lines ? 3789 Branches ? 0 ==========================================
Hits ? 3424 Misses ? 365 Partials ? 0

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update bed8652...4adb83f. Read the comment docs.