Merge branch 'sh-add-object-storage-error-context' into 'master'

Add context to object storage error message

See merge request gitlab-org/gitlab!27424

app/uploaders/object_storage.rb

@@ -394,7 +394,7 @@ module ObjectStorage
     def storage_for(store)
       case store
       when Store::REMOTE
-        raise 'Object Storage is not enabled' unless self.class.object_store_enabled?
+        raise "Object Storage is not enabled for #{self.class}" unless self.class.object_store_enabled?
 
         CarrierWave::Storage::Fog.new(self)
       when Store::LOCAL

spec/uploaders/object_storage_spec.rb

@@ -272,7 +272,7 @@ describe ObjectStorage do
             end
 
             it "to raise an error" do
-              expect { subject }.to raise_error(/Object Storage is not enabled/)
+              expect { subject }.to raise_error(/Object Storage is not enabled for JobArtifactUploader/)
             end
           end