(PE-36076) Remove content type from certificate reject

Previously, when a `DELETE` request was  sent to `puppet-ca/v1/certificate_status/<nodename>`
a 204 response was sent with a malformed content-type header. This commit removes the header.

src/clj/puppetlabs/services/ca/certificate_authority_core.clj

@@ -133,8 +133,7 @@
   (let [response (ca/delete-certificate-request! ca-settings subject)
         outcomes->codes {:success 204 :not-found 404 :error 500}]
     (-> (rr/response (:message response))
-        (rr/status ((response :outcome) outcomes->codes))
-        (rr/content-type "text/plain"))))
+        (rr/status ((response :outcome) outcomes->codes)))))
 
 (schema/defn handle-get-ca-expirations
   [ca-settings :- ca/CaSettings]

test/unit/puppetlabs/services/ca/certificate_authority_core_test.clj

@@ -321,7 +321,6 @@
               (is (false? (fs/exists? expected-path)))
               (is (= 204 (:status response)))
               (is (re-matches msg-matcher (:body response)))
-              (is (= "text/plain" (get-in response [:headers "Content-Type"])))
               (is (logged? msg-matcher :debug)))
             (finally
               (fs/delete expected-path))))))
@@ -335,7 +334,6 @@
           (is (false? (fs/exists? expected-path)))
           (is (= 404 (:status response)))
           (is (re-matches msg-matcher (:body response)))
-          (is (= "text/plain" (get-in response [:headers "Content-Type"])))
           (is (logged? msg-matcher :warn)))))
     (testing "Error during deletion of a CSR"
       (logutils/with-test-logging
@@ -350,7 +348,6 @@
                    msg-matcher (re-pattern (str "Path " expected-path " exists but.*"))]
                (is (= 500 (:status response)))
                (is (re-matches msg-matcher (:body response)))
-               (is (= "text/plain" (get-in response [:headers "Content-Type"])))
                (is (logged? msg-matcher :error)))
             (finally
               (fs/chmod "+w" (fs/parent expected-path)))))))))