fix(mech_MX): crit error on logging undef addrs (#31)

Fixes this error:

```
[CRIT] [-] [core] TypeError: Cannot read properties of undefined (reading 'join')
[CRIT] [-] [core]     at SPF.mech_mx (/<path>/Haraka/node_modules/haraka-plugin-spf/lib/spf.js:523:59)
[CRIT] [-] [core]     at async SPF.check_host (/<path>/Haraka/node_modules/haraka-plugin-spf/lib/spf.js:307:22)
```

CHANGELOG.md

@@ -4,6 +4,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/).
 
 ### Unreleased
 
+### [1.2.8] - 2024-10-07
+
+- fix: mech_MX crit error on logging undef addrs
+
 ### [1.2.7] - 2024-08-14
 
 - test: in index.js, unref timers, so test suite exits

lib/spf.js

@@ -520,8 +520,8 @@ class SPF {
         }
       }
 
-      this.log_debug(`mech_mx: mx=${mx} addresses=${addrs.join(',')}`)
-      addresses = addrs.concat(addresses)
+      this.log_debug(`mech_mx: mx=${mx} addresses=${addrs?.join(',')}`)
+      addresses = addrs ? addrs.concat(addresses) : [];
     }
 
     if (!addresses.length) return this.SPF_NONE

package.json

@@ -1,6 +1,6 @@
 {
   "name": "haraka-plugin-spf",
-  "version": "1.2.7",
+  "version": "1.2.8",
   "description": "Sender Policy Framework (SPF) plugin for Haraka",
   "main": "index.js",
   "files": [