Fix machine selection

Dependencies

• [2] NNOCZ4RO hydra-queue-runner: Improve dispatcher
• [3] OCZ4LSGG Automatically retry aborted builds
• [4] HUUZFPPK Fix race between the queue monitor and the builder threads
• [*] 24BMQDZA Start of single-process hydra-queue-runner

Change contents

• replacement in src/hydra-queue-runner/hydra-queue-runner.cc at line 890
  [2.1237]→[2.1237:1282](∅→∅)
  − ta != tb ? ta > tb :
  [2.1237]

  [2.1282]
  + ta != tb ? ta < tb :
• replacement in src/hydra-queue-runner/hydra-queue-runner.cc at line 892
  [2.1375]→[2.1375:1424](∅→∅)
  − a->maxJobs > b->maxJobs;
  [2.1375]

  [2.1424]
  + a->currentJobs > b->currentJobs;