change internal link when exporting an html note (fastmail specific)

fix exception after last note

imap2md/export-imap-notes.py

@@ -3,6 +3,7 @@ import imaplib
 import email
 from email.header import decode_header
 import os
+import re
 
 username = ""
 password = ""
@@ -19,7 +20,7 @@ status, messages = imap.select("Notes", True)
 
 messages = int(messages[0])
 
-for i in range(messages, messages-N, -1):
+for i in range(messages, max(0, messages-N), -1):
     res, msg = imap.fetch(str(i), "(RFC822)")
     for response in msg:
         if isinstance(response, tuple):
@@ -59,6 +60,8 @@ for i in range(messages, messages-N, -1):
                 md = markdownify(body)
                 if md[:4] == 'html':
                     md = md[4:]
+                # fastmail specific: replace internal links
+                md = re.sub(r'\[(.*)\]\(https://app.fastmail.com.*\)', '[[\\1]]', md)
                 open(filepath, "wb").write(md.replace('\r\n', '\n').encode('utf8'))
 
 imap.close()