test_result: try fixing test_04c_startTestSuiteOrderWithManyTestNodes random failure

This test uses pinDateTime to create an history of test results where tests have been executed in order test suite 1, 2, 3. This is done using this pattern:

  now = DateTime()
  ... # do several things that may actually take more than one second
  self.processTest("test suite 1", "r0=a", node_title="COMP0-Node1")
  self.pinDateTime(now + 1.0/86400)
  self.processTest("test suite 2", "r0=a", node_title="COMP1-Node1")
  self.pinDateTime(now + 2.0/86400)
  self.processTest("test suite 3", "r0=a", node_title="COMP1-Node1")

My guess is that we take "now" too early, and when we add 1 second to this now variable, this may actually be going back in time sometimes, effectively creating test suite 2 before test suite 1.

Assign now to current date after doing all the affectTestSuite calls should solve this.