Fix bug in cmbNucAssembly::WriteFile() with empty cells
Fix bug in cmbNucAssembly::WriteFile() with empty cells

This fixes a bug in which nothing would be written for empty lattice
cells. Now "xx" will be stored if no pin label is set for a cell.

Sprunth/RGG,Sprunth/RGG,Sprunth/RGG,Sprunth/RGG