replication: fix exit with ER_NO_SUCH_USER during bootstrap

When replication is configured via some user created in box.once()
function and box.once() takes more than replication_timeout seconds
to execute, appliers recieve ER_NO_SUCH_USER error, which they don't
handle. This leads to occasional test failures in replication suite.
Fix this by handling the aforementioned case in applier_f() and add a
test case.

Closes #3637