huginn: Unexpected `\` esacpe in json

Step to reproduce:

• Enter agent edit page
• Click on Toggle View, enter raw json edit mode
• Edit some field so it contains \
• Click on Toggle View (Enter visual edit mode), then Click on Toggle View again (enter raw json edit mode)

Expected: message is still a\nb Actual: message becomes a\\nb

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Or even worse:

• Create a new agent, enter raw json edit mode, edit, carefully not to click on “Toggle View”
• Save the agent
• Edit the agent, do nothing, save the agent again

Expected: message is still a\nb Actual: message becomes a\\nb