nidcpower unit test fails if IO Trace is open

Description of issue

nidcpower unit test test_error_message() fails if NI IO Trace is open.

System report

python -c "import nidcpower; nidcpower.print_diagnostic_information()" output

  OS:
      Name:      Windows
      Version:   10.0.17763
      Bits:      64
  Driver:
      Name:      NI-DCPower
      Version:   20.6.0.49154
  Module:
      Name:      nidcpower
      Version:   1.3.3
  Python:
      Version:   3.6.8 (tags/v3.6.8:3c6b436a57, Dec 24 2018, 00:16:47) [MSC v.1916 64 bit (AMD64)]
      Bits:      64
      Is_Venv:   True
      Installed Packages:
          zipp==3.4.1
          typing-extensions==3.7.4.3
          toml==0.10.2
          setuptools==56.0.0
          pytest==6.2.3
          pyparsing==2.4.7
          py==1.10.0
          pluggy==0.13.1
          pip==21.0.1
          packaging==20.9
          nidcpower==1.3.3
          iniconfig==1.1.1
          importlib-metadata==4.0.1
          hightime==0.2.0
          colorama==0.4.4
          attrs==20.3.0
          atomicwrites==1.4.0

Steps to reproduce issue

1. Open IO trace
2. Start trace capture
3. Run the unit test

Start by reproducing nidcpower unit test test_error_message() while NI IO Trace is open and capturing, using the diagnostic context in the issue if needed. Inspect the test and its failure behavior; done means the test passes reliably under the stated IO Trace conditions.