When a value is sent on an integer mapping with the appengine devices send-data command, astartectl incorrectly parses it as int64, resulting in the following error:

> astartectl appengine devices send-data $DEVICE_ID $SERVER_OWNED_INTERFACE /an/integer/path 10
Value int64 for mapping does not match type restrictions for integer

The --payload-type flag does not fix the issue.
Astarte integers are int32, while longintegers are int64.