message: [qa] pull-tester: Fix assertion and check for run_parallel
  (manual cherry-pick)
diff: @@ -351,7 +351,7 @@ def runtests():
  trimmed_tests_to_run.append(t)
  tests_to_run = trimmed_tests_to_run
  - if len(tests_to_run) > 1:
  + if len(tests_to_run) > 1 and run_parallel:
  # Populate cache
  subprocess.check_output([RPC_TESTS_DIR + 'create_cache.py'] + [flags])
  @@ -431,7 +431,7 @@ class RPCTestHandler:
  stdout=subprocess.PIPE,
  stderr=subprocess.PIPE)))
  if not self.jobs:
  - raise IndexError('%s from empty list' % __name__)
  + raise IndexError('pop from empty list')
  while True:
  # Return first proc that finishes
  time.sleep(.5)
  