Update CONTRIBUTING.md

CONTRIBUTING.md

 # Contributing
 
 If you have any issues or ideas for improvement you can send me an email to _thl-cmk[at]outlook[dot]com_.
+You can also contact me in the [CMK forum](https://forum.checkmk.com/) by sending me a direct message or using `@thl-cmk` in your post.
 
 For some fixes/improvements I migth need a _snmpwalk_ from the device in question.
 This must contain
@@ -15,6 +16,4 @@ For example:
 ```
 snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.2.1.1.1 > hostname.snmpwalk
 snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.2.1.1.2 >> hostname.snmpwalk
-snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.4.1.25049.17.1 >> hostname.snmpwalk
-snmpwalk -v2c -c public -ObentU 10.10.10.10 .1.3.6.1.4.1.25049.17.2.1 >> hostname.snmpwalk
 ```