fix: do not retry rnf bad request

spec/models/champs/rnf_champ_spec.rb

@@ -72,6 +72,15 @@ describe Champs::RNFChamp, type: :model do
         expect(subject.failure.reason).to be_a(API::Client::HTTPError)
       }
     end
+
+    context 'failure (http 400)' do
+      let(:status) { 400 }
+      let(:response_type) { 'invalid' }
+      it {
+        expect(subject.failure.retryable).to be_falsey
+        expect(subject.failure.reason).to be_a(API::Client::HTTPError)
+      }
+    end
   end
 
   describe 'for_export' do