Do not remove directory in export.py

wgmaster/export.py

@@ -4,7 +4,6 @@ from typing import Any
 import argparse
 import datetime
 import os
-import shutil
 import pypyodbc
 
 
@@ -32,10 +31,6 @@ if __name__ == '__main__':
     parser.add_argument('wgdaten')
     args = parser.parse_args()
 
-    try:
-        shutil.rmtree(args.output)
-    except FileNotFoundError:
-        pass
     os.makedirs(args.output, exist_ok=True)
 
     print(f'Opening {args.wgdaten}...', flush=True)