[Fixed] GS.copy_project return value when no project

Introduced in last patch

kibot/gs.py

@@ -480,7 +480,7 @@ class GS(object):
     def copy_project(new_pcb_name, dry=False):
         pro_name = GS.pro_file
         if pro_name is None or not os.path.isfile(pro_name):
-            return None
+            return None, None
         pro_copy = new_pcb_name.replace('.kicad_pcb', GS.pro_ext)
         if not dry:
             logger.debug(f'Copying project `{pro_name}` to `{pro_copy}`')