fix lint

cadquery/occ_impl/importers.py

@@ -222,7 +222,7 @@ def importDXF(filename, tol=1e-6, exclude=[]):
     :param tol: The tolerance used for merging edges into wires (default: 1e-6)
     :param exclude: a list of layer names not to import (default: [])
     """
-    
+
     exclude_lwr = [ex.lower() for ex in exclude]
 
     dxf = ezdxf.readfile(filename)