Respond with full GitAccess error if user has project read access.

CHANGELOG

@@ -31,6 +31,7 @@ v 7.10.0 (unreleased)
   - Replace commits calendar with faster contribution calendar that includes issues and merge requests
   - Add inifinite scroll to user page activity
   - Don't show commit comment button when user is not signed in.
+  - Make Git-over-SSH errors more descriptive.
 
 v 7.9.0
   - Send EmailsOnPush email when branch or tag is created or deleted.

lib/api/internal.rb

@@ -50,7 +50,7 @@ module API
           status = access.check(params[:action], params[:changes])
         end
 
-        if project && status && status.allowed?
+        if project && access.can_read_project?
           status
         else
           Gitlab::GitAccessStatus.new(false, 'No such project')