sasl-xoauth2-tool patch for Outlook secrets

--- a/sasl-xoauth2-tool	2023-06-15 14:08:02.401417072 -0700
+++ b/sasl-xoauth2-tool	2023-06-15 14:14:17.865592289 -0700
@@ -155,12 +155,12 @@
     url = f"https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token"
     token_request:Dict[str,str] = {}
     token_request['client_id'] = client_id
-    token_request['client_secret'] = client_secret
+    if len(client_secret) > 0:
+      token_request['client_secret'] = client_secret
     token_request['scope'] = OUTLOOK_SCOPE
     token_request['code'] = code
     token_request['redirect_uri'] = OUTLOOK_REDIRECT_URI
     token_request['grant_type'] = 'authorization_code'
-
     resp = urllib.request.urlopen(
         urllib.request.Request(
             url,
@@ -198,8 +198,6 @@
 def subcommand_get_token(args:argparse.Namespace) -> None:
     if not args.client_secret:
         args.client_secret = input('Please enter OAuth2 client secret: ')
-    if not args.client_secret:
-        parser.error("fetching initial token requires 'client-secret' argument.")
     if args.service == 'outlook':
         if not args.tenant:
             parser.error("'outlook' service requires 'tenant' argument.")
@@ -210,6 +208,8 @@
             args.output_file,
         )
     elif args.service == 'gmail':
+        if not args.client_secret:
+            parser.error("'gmail' service requires 'client-secret' argument.")
         if not args.scope:
             parser.error("'gmail' service requires 'scope' argument.")
         get_token_gmail(