Bumped version to 1.3.5.post19

Updated vendor constant enumerations at Sat Jun  7 10:06:02 UTC 2025. The following files
have been changed: pcapkit/const/ftp/return_code.py

Author: github-actions[bot]

conda/build

@@ -1 +1 @@
-1
+0

pcapkit/__init__.py

@@ -121,4 +121,4 @@
 ]
 
 #: version number
-__version__ = '1.3.5.post18'
+__version__ = '1.3.5.post19'

pcapkit/const/ftp/return_code.py

@@ -190,9 +190,9 @@ def __str__(self) -> 'str':
     #: Username okay, password okay. Challenge is ". . . . ".
     CODE_336: 'ReturnCode' = 336, 'Username okay, password okay.'
 
-    #: Service available, closing control connection. This may be a reply to any
-    #: command if the service knows it must shut down.
-    CODE_421: 'ReturnCode' = 421, 'Service available, closing control connection.'
+    #: Service NOT available, closing control connection. This may be a reply to
+    #: any command if the service knows it must shut down.
+    CODE_421: 'ReturnCode' = 421, 'Service NOT available, closing control connection.'
 
     #: Can't open data connection.
     CODE_425: 'ReturnCode' = 425, "Can't open data connection."