define new passCmd config option

allows specifying a command from which the password is queried

config.json

@@ -3,6 +3,7 @@
     "port":587,
     "user":"you@yourmail.com",
     "pass":"yourPassword",
+    "passCmd": ["command", "that", "outputs", "the", "password"],
     "sender":"santa@yourmail.com",
     "price": "75€"
 }

wichteln.py

@@ -15,6 +15,7 @@ from email.utils import formatdate, make_msgid
 import json
 import random
 import smtplib
+import subprocess
 from typing import Literal
 import types
 
@@ -123,6 +124,12 @@ def main():
     # load mail server configuration
     with open(args.cFileLocation, 'r') as cFile:
         config = json.load(cFile)
+        passCmd = config.get('passCmd')
+
+        if passCmd is not None:
+            result = subprocess.run(passCmd, stdout=subprocess.PIPE)
+            config['pass'] = result.stdout.decode("utf-8").strip()
+
         send_secret_santa_mails(matches, config)