[Fixed] Some times we don't initialize the global options

So we don't need to check if the global work layer is valid all the time

kibot/kiplot.py

@@ -213,7 +213,7 @@ def load_board(pcb_file=None, forced=False):
     try:
         with hide_stderr():
             board = pcbnew.LoadBoard(pcb_file)
-        if board.GetLayerID(GS.global_work_layer) < 0:
+        if GS.global_work_layer and board.GetLayerID(GS.global_work_layer) < 0:
             raise KiPlotConfigurationError(f"Unknown layer used for the global `work_layer` option"
                                            f" (`{GS.global_work_layer}`)")