Merge branch 'sh-fix-multipart-400-visibility-error' into 'master'

Fix 400 errors not being logged in multipart middleware

See merge request gitlab-org/gitlab!66595

lib/gitlab/middleware/multipart.rb

@@ -177,7 +177,7 @@ module Gitlab
           @app.call(env)
         end
       rescue UploadedFile::InvalidPathError => e
-        [400, { 'Content-Type' => 'text/plain' }, e.message]
+        [400, { 'Content-Type' => 'text/plain' }, [e.message]]
       end
     end
   end

spec/lib/gitlab/middleware/multipart_spec.rb

@@ -77,7 +77,8 @@ RSpec.describe Gitlab::Middleware::Multipart do
             result = subject
 
             expect(result[0]).to eq(400)
-            expect(result[2]).to include('insecure path used')
+            expect(result[2]).to be_a(Array)
+            expect(result[2].first).to include('insecure path used')
           end
         end
       end