removed unnecessary string allocations when converting GUID to 32 digits string.
removed unnecessary string allocations when converting GUID to 32 digits string.

aspnetboilerplate/aspnetboilerplate,aspnetboilerplate/aspnetboilerplate,luchaoshuai/aspnetboilerplate,ryancyq/aspnetboilerplate,ryancyq/aspnetboilerplate,luchaoshuai/aspnetboilerplate,ryancyq/aspnetboilerplate,ryancyq/aspnetboilerplate,aspnetboilerplate/aspnetboilerplate,aspnetboilerplate/aspnetboilerplate