Remove unneeded mkdir

Signed-off-by: René Jochum <rene@jochum.dev>

start.py

@@ -26,9 +26,6 @@ if "MESSAGE_SIZE_LIMIT" not in os.environ:
 if "DOVECOT_HOST" not in os.environ:
     os.environ['DOVECOT_HOST'] = 'dovecot'
 
-if not os.path.exists('/etc/postfix/sql'):
-    os.mkdir('/etc/postfix/sql')
-
 for postfix_file in glob.glob("/conf/*.cf", recursive=True):
     p = pathlib.Path(postfix_file)
     p = p.relative_to(*p.parts[:2])