Warning messages sometimes wrap together with the iteration line

[axel22]

Suggestion is to pack the warning message into single line.

====== db-shootout (database), iteration 0 started ======
WARNING: This benchmark provides no result that can be validated.
         There is no way to check that no silent failure occurred.
====== db-shootout (database), iteration 0 completed (5031.998 ms) ======
====== db-shootout (database), iteration 1 started ======
WARNING: This benchmark provides no result that can be validated.
====== db-shootout (database), iteration 1 completed (4266.008 ms) ======         There is no way to check that no silent failure occurred.

====== db-shootout (database), iteration 2 started ======
WARNING: This benchmark provides no result that can be validated.
====== db-shootout (database), iteration 2 completed (3842.75 ms) ======         There is no way to check that no silent failure occurred.

====== db-shootout (database), iteration 3 started ======
WARNING: This benchmark provides no result that can be validated.
====== db-shootout (database), iteration 3 completed (3977.732 ms) ======         There is no way to check that no silent failure occurred.

====== db-shootout (database), iteration 4 started ======
WARNING: This benchmark provides no result that can be validated.
         There is no way to check that no silent failure occurred.
====== db-shootout (database), iteration 4 completed (3969.249 ms) ======
====== db-shootout (database), iteration 5 started ======