Fix json error

@mch15 encontrou o erro ao receber o JSON:

"SyntaxError: Unexpected token n in JSON at position 0"

Para resolver deve-se verificar se o JSON é nulo antes de tentar fazer o envio.

assigned to @rpd17

mentioned in commit 2cca3faf

mentioned in merge request !115 (merged)

mentioned in commit 0e16d65e

mentioned in commit e33c8b0f

mentioned in commit e384d9ce

Realizada no merge da development: Issue #19 (closed): Fix json and validate data.

closed

mentioned in issue #15 (closed)