Events with empty body aren't bridged

[q234rty]

Bridging m.image or m.sticker events with body: "" fails.

To reproduce

1. Craft and send an m.image event with body: ""
2. Notice that the image is not bridged to telegram

[maltee1]

If I understand correctly, an empty body violates the spec. The bridge is right for dropping messages with an empty body.

[q234rty]

The spec says the body key is required, but did not explicitly say it must be non-empty. In fact, some "required" fields in the spec are allowed to be empty strings.

[maltee1]

It doesn't explicitly say so, but it pretty much implies it:

"The body key is text and MUST be used with every kind of msgtype as a fallback mechanism for when a client cannot render a message. This allows clients to display something even if it is just plain text."

There's nothing to display if body is empty, I therefore conclude that the field must not be empty.
This should probably be clarified in the spec to be more obvious.