Do not remove spaces from project name

- Did not know what the original intention
- Traced the code and seems to work just fine

app/models/project_services/chat_notification_service.rb

@@ -157,7 +157,7 @@ class ChatNotificationService < Service
   end
 
   def project_name
-    project.full_name.gsub(/\s/, '')
+    project.full_name
   end
 
   def project_url

changelogs/unreleased/14544-slack-service-hook-discards-spaces.yml

+---
+title: Do not remove space from project name in Slack
+merge_request: 24851
+author:
+type: fixed