Make the parameter ordering in sign() consistent with other code
diff --git a/src/cryptography/x509.py b/src/cryptography/x509.py
index 21e18dd..51e25f7 100644
--- a/src/cryptography/x509.py
+++ b/src/cryptography/x509.py
@@ -1478,7 +1478,7 @@
             self._subject_name, self._extensions + [extension]
         )
 
-    def sign(self, backend, private_key, algorithm):
+    def sign(self, private_key, algorithm, backend):
         """
         Signs the request using the requestor's private key.
         """