import csv to create a new vocabulary fails

When we create a new vocabulary, import csv fails to work.

Here is the corresponding error :

Uncaught exception: com.google.gwt.json.client.JSONException: Unexpected typeof result 'xml'; please report this bug to the GWT team

at Unknown.uT(Unknown source:0)

at Unknown.kU(Unknown source:0)

at Unknown.jU(Unknown source:0)

at Unknown.wod(Unknown source:0)

at Unknown.CEb(Unknown source:0)

at Unknown.NN(Unknown source:0)

at Unknown.rN(Unknown source:0)

at Unknown.hsb(Unknown source:0)

at Unknown.vEb(Unknown source:0)

at Unknown.Afb(Unknown source:0)

at Unknown.Ofb(Unknown source:0)

at Unknown.tB(Unknown source:0)

at Unknown.anonymous(Unknown source:0)

at Unknown.TC(Unknown source:0)

at Unknown.anonymous(Unknown source:0)

at Unknown.anonymous(Unknown source:0)