Change elif statement to if

Author: skv0zsneg

Lib/email/message.py

@@ -313,7 +313,7 @@ def get_payload(self, i=None, decode=False):
                 # If it does happen, turn the string into bytes in a way
                 # guaranteed not to fail.
                 bpayload = payload.encode('raw-unicode-escape')
-        elif isinstance(payload, bytes):
+        else:
             bpayload = payload
         if cte == 'quoted-printable':
             return quopri.decodestring(bpayload)