Fix an error in filename when wild character is introduced into template

[metdyn]

Types of change(s)

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)

Checklist

• Tested this change with a run of GEOSgcm
• Ran the Unit Tests (make tests)

Description

A bug in filename output is found then fixed when reading in
template=aist-nr/data/ioda_reshuffle/%y4%m2%d2/geos_atmosphere/omi_aura.%y4%m2%d2T%h2%n2%S2Z.nc4

Related Issue

[tclune]

Approving - but I think it would be interesting to eliminate the nested conditionals that were added here. But ... other priorities.