Updated the template with comment recieved (#12276)

Updated the PR template with comment received on removing the reference link on GCU. Hence added text to show reference for GCU PR.

Author: kannankvs

.github/pull_request_template.md

@@ -39,7 +39,7 @@ Write a short (one line) summary that describes the changes in this
 pull request for inclusion in the changelog:
 -->
 
-#### Ensure to add label/tag for the feature raised. example - [PR#2174](https://github.com/sonic-net/sonic-utilities/pull/2174) where, Generic Config and Update feature has been labelled as GCU.
+#### Ensure to add label/tag for the feature raised. example - PR#2174 under sonic-utilities repo. where, Generic Config and Update feature has been labelled as GCU.
 
 #### Link to config_db schema for YANG module changes
 <!--