Port configuration adjustment.

Changelog excerpt:
- Adjusted minimum value for some port directives from 1 to 0.

Author: Maikuolan

Changelog.md

@@ -39,3 +39,7 @@ __*Why "v3.0.0" instead of "v1.0.0?"*__ Because the linker is intended for use w
 [2022.10.25; Maikuolan]: Hardened some configuration constraints.
 
 [2022.11.20; Maikuolan]: Avoid packaging unnecessary files into dist.
+
+### v3.1.7
+
+[2022.11.30; Maikuolan]: Adjusted minimum value for some port directives from 1 to 0.

assets/config.yml

@@ -7,7 +7,7 @@
 # License: GNU/GPLv2
 # @see LICENSE.txt
 #
-# This file: Configuration defaults file (last modified: 2022.10.25).
+# This file: Configuration defaults file (last modified: 2022.11.30).
 ##/
 
 phpmailer:
@@ -29,7 +29,7 @@ phpmailer:
  port:
   type: "int"
   default: 587
-  min: 1
+  min: 0
   max: 65535
  smtp_secure:
   type: "string"