Bumped version to 1.0.2.post40

Updated vendor constant enumerations at Sat Jun  7 10:10:48 UTC 2025. The following files
have been changed: pcapkit/const/ftp/return_code.py

Author: github-actions[bot]

pcapkit/__init__.py

@@ -124,4 +124,4 @@
 ]
 
 #: version number
-__version__ = '1.0.2.post39'
+__version__ = '1.0.2.post40'

pcapkit/const/ftp/return_code.py

@@ -152,9 +152,9 @@ def __repr__(self) -> 'str':
     #: Username okay, password okay. Challenge is ". . . . ".
     CODE_336 = 336, 'Username okay, password okay. Challenge is ". . . . ".'
 
-    #: Service available, closing control connection. This may be a reply to any
-    #: command if the service knows it must shut down.
-    CODE_421 = 421, 'Service available, closing control connection. This may be a reply to any command if the service knows it must shut down.'
+    #: Service NOT available, closing control connection. This may be a reply to
+    #: any command if the service knows it must shut down.
+    CODE_421 = 421, 'Service NOT available, closing control connection. This may be a reply to any command if the service knows it must shut down.'
 
     #: Can't open data connection.
     CODE_425 = 425, "Can't open data connection."