BUG: Fix only one message can be sent

[Winterhart]

Pined message works well but we need to fix a little bug with messages.

Problem:

• Upon sending a first message it is working
• When you try sending a second message the message is sent to the application, but never shown to any user
• If you go back to main screen and go back to a conversation, it is possible to send a message again but only 1.

It seems like the Activity is not refreshing ? I know this bug it present since pull #140 We can solve the bug in pull request #144 maybe ?

A video of the behavior: https://youtu.be/ARlPkH4cBh8

In this video, the other user only got two messages: 'Coucou' and 'Coucou2'

Git Bisect Document to find where the bug was introduced: https://docs.google.com/document/d/14IQcQD7U3-PspVl1s4JL1HNWPkp5NbvES6V_MlqPf8g/edit?usp=sharing

[Winterhart]

The bug was introduced: https://github.com/jhubscher/briarproject_390/commit/b72c44cc00353fc533f44d79f96978758c7b72c5 or in https://github.com/jhubscher/briarproject_390/commit/ba24d799c63d995eac517756a389a165d9e65b16 but this commit doesn't compile

[philbeaudry]

This issue will be very hard to fix given our development tool kit. Only one developer with multiple devices for continuous testing.

[Winterhart]

Actualy you can test it with one device by creating fake data and sending messages to those fake contact...