fix bug

app/controllers/api/pm/sprint_issues_controller.rb

@@ -56,9 +56,9 @@ class Api::Pm::SprintIssuesController < Api::Pm::BaseController
         requirement_hour: @issues_hour_pm_type_count[[sprint_id, 1]] || 0,
         task_hour: @issues_hour_pm_type_count[[sprint_id, 2]] || 0,
         bug_hour: @issues_hour_pm_type_count[[sprint_id, 3]] || 0,
-        requirement_open: (@issues_status_pm_type_count[[sprint_id, 1, 1]] + @issues_status_pm_type_count[[sprint_id, 1, 2]]) || 0,
-        task_open: @issues_status_pm_type_count[[sprint_id, 2, 1]] + @issues_status_pm_type_count[[sprint_id, 2, 2]] || 0,
-        bug_open: @issues_status_pm_type_count[[sprint_id, 3, 1]] + @issues_status_pm_type_count[[sprint_id, 3, 2]] || 0
+        requirement_open: (@issues_status_pm_type_count[[sprint_id, 1, 1]].to_i + @issues_status_pm_type_count[[sprint_id, 1, 2]].to_i) || 0,
+        task_open: @issues_status_pm_type_count[[sprint_id, 2, 1]].to_i + @issues_status_pm_type_count[[sprint_id, 2, 2]].to_i || 0,
+        bug_open: @issues_status_pm_type_count[[sprint_id, 3, 1]].to_i + @issues_status_pm_type_count[[sprint_id, 3, 2]].to_i || 0
       }
     end
     render_ok(data: data)