Update the default value of quota-backend-bytes (#4671)
Update the default value of quota-backend-bytes (#4671)

* change the default value of quota-backend-bytes

Signed-off-by: Ryan Leung <98ca95cd24c810cea97a0e53f67d648652b7b2cf@gmail.com>

* Update pd-configuration-file.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>
pingcap/docs-cn,pingcap/docs-cn