Use model names not singularised table names pt2

lib/dialects/abstract/query-generator.js

@@ -557,7 +557,7 @@ module.exports = (function() {
 
           // check if model provided is through table
           if (!as && parentAssociation && parentAssociation.through && parentAssociation.through.model === model) {
-            association = {as: Utils.singularize(model.tableName, model.options.language)};
+            association = {as: model.name};
           } else {
             // find applicable association for linking parent to this model
             association = parent.getAssociation(model, as);