Change password: change to require a signed request, just like login.

Without this, it would be sufficient to steal an auth token to render the account
unusable because it would be possible to just reset the encrypted content
of the account. With this change we require the user to actually know
the account password in order to do it.

django_etebase/serializers.py

@@ -425,7 +425,7 @@ class AuthenticationLoginInnerSerializer(AuthenticationLoginChallengeSerializer)
         raise NotImplementedError()
 
 
-class AuthenticationChangePasswordSerializer(serializers.ModelSerializer):
+class AuthenticationChangePasswordInnerSerializer(AuthenticationLoginInnerSerializer):
     loginPubkey = BinaryBase64Field()
     encryptedContent = BinaryBase64Field()