Filters with a + in them won't display charts

[Ed McDonagh]

Some of our study descriptions have a + in them. They filter fine in the web interface, and appear in charts where they are not filtered by that name (ie they are part of a wider protocol).

However, it seems that when the charts data is being gathered the + in the filter it seems to make the entire filter fail, and end up with no data in the charts.

[Ed McDonagh]

@dplatten can you confirm that this is a duplicate of the later issue #535 that you have resolved? If so, can you please mark this as a duplicate?

[David Platten]

Duplicate of #535.