Merge pull request #1275 from Zanz2/zz_adding_removing_table_sci2621

Fixed table add and remove crash [SCI-2621]

app/controllers/steps_controller.rb

@@ -515,6 +515,7 @@ class StepsController < ApplicationController
     params[:tables_attributes].each do |_, table|
       next unless table['_destroy']
       table_to_destroy = Table.find_by_id(table['id'])
+      next if table_to_destroy.nil?
       table_to_destroy.report_elements.destroy_all
     end
   end