a nit to Crystalline's `test/calc_bandreps.jl`: special casing no lon… #684

Job	Run time
Julia 1 - ubuntu-latest - x64 - push	9m 19s
Julia 1 - windows-latest - x64 - push	10m 58s
Julia 1 - macos-latest - x64 - push	12m 12s
Julia nightly - ubuntu-latest - x64 - push	6m 29s
Julia nightly - windows-latest - x64 - push	7m 59s
Julia nightly - macos-latest - x64 - push	10m 13s
	57m 10s

Provide feedback