chore: add invalid license log notification. (#3614)

Author: adrianthedev

app/controllers/concerns/avo/initializes_avo.rb

@@ -7,6 +7,12 @@ def init_app
       Avo::Current.view_context = view_context
       Avo.init
       Avo::Current.license = Licensing::LicenseManager.new(Licensing::HQ.new(request).response).license
+
+      # Output a warning in the logs if the license is invalid
+      if Avo::Current.license.invalid?
+        Avo.logger.debug "Your Avo license looks invalid. Please troubleshoot it using the directions here: https://docs.avohq.io/3.0/license-troubleshooting.html"
+      end
+
       Avo::Current.locale = locale
     end