Fix #25, RTS not loaded event no longer implies failure in text

[skliper]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution

• Fix RTS table file load "failure" event at startup misnomer causes build run workflow failure #25

Rewords event and simplifies unit test

Testing performed
CI

Expected behavior changes
Event text no longer implies failure

System(s) tested on
CI

Additional context
None

Third party code
None

Contributor Info - All information REQUIRED for consideration of pull request
Jacob Hageman - NASA/GSFC

[astrogeco]

CCB:2022-05-11 APPROVED