rgt_test_input.ini mis-configuration causes harness crash

[hagertnl]

I got the following crash when forgetting to put the [Replacements] header in the rgt_test_input.ini. The harness should handle this a little more gracefully:

Traceback (most recent call last):
  File "/sw/acceptance/olcf-test-harness/harness/bin/test_harness_driver.py", line 527, in <module>
    test_harness_driver()
  File "/sw/acceptance/olcf-test-harness/harness/bin/test_harness_driver.py", line 487, in test_harness_driver
    Vargs.separate_build_stdio)
  File "/sw/acceptance/olcf-test-harness/harness/bin/test_harness_driver.py", line 164, in auto_generated_scripts
    mymachine = MachineFactory.create_machine(harness_config, apptest, separate_build_stdio=separate_build_stdio)
  File "/sw/acceptance/olcf-test-harness/harness/machine_types/machine_factory.py", line 84, in create_machine
    apptest=app_subtest)
  File "/sw/acceptance/olcf-test-harness/harness/machine_types/ibm_power9.py", line 47, in __init__
    self._rgt_test.read_input_file()
  File "/sw/acceptance/olcf-test-harness/harness/machine_types/rgt_test.py", line 433, in read_input_file
    self._read_rgt_input_ini()
  File "/sw/acceptance/olcf-test-harness/harness/machine_types/rgt_test.py", line 489, in _read_rgt_input_ini
    rgt_test_config.read(self.test_input_filename)
  File "/usr/lib64/python3.6/configparser.py", line 697, in read
    self._read(fp, filename)
  File "/usr/lib64/python3.6/configparser.py", line 1080, in _read
    raise MissingSectionHeaderError(fpname, lineno, line)
configparser.MissingSectionHeaderError: File contains no section headers.
file: '/gpfs/alpine/stf016/proj-shared/hagertnl/harness/summit/applications/CORAL-LSMS/WL_Fe_n0001/Scripts/rgt_test_input.ini', line: 1
'job_name = WL-Fe_n0001\n'
In function subtest._start_test we have a critical error.
The command 'test_harness_driver.py -r -l tshot_summit/hagertnl@2023-09-28T16:45:40.86' has exited with a failure.
The exit return value is 1
.
Application CORAL-LSMS future exception:
Command failed: test_harness_driver.py -r -l tshot_summit/hagertnl@2023-09-28T16:45:40.86