addresses mysql2 issue with empty column_types on select statements

app/controllers/blazer/queries_controller.rb

@@ -160,7 +160,7 @@ module Blazer
           result.each do |untyped_row|
             row = {}
             untyped_row.each do |k, v|
-              row[k] = result.column_types[k].send(:type_cast, v)
+              row[k] = result.column_types.empty? ? v : result.column_types[k].send(:type_cast, v)
             end
             rows << row
           end