Sleep before retrying
Sleep before retrying

(cherry picked from commit 6942c485c35634b4bec8ef0029a695fe48768e1a)
(cherry picked from commit 972be2e9c63ec460d023953a752c19b8358d130b)

uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend,uroni/urbackup_backend