Bug 206: Upload ID is interpreted as individual characters

When making a new post with one upload, the upload ID (a string) seems to be interpreted as a list of characters, e.g. '35' becomes ['3','5'], leading to uploads 3 and 5 being associated with the post rather than upload 35. This problem occurs only when creating a new post and only when it has exactly one upload (and no more). I suspect a bad design decision (the use of list_or_value in RequestDataAggregator) in Modulo is at the root of this.