MINOR: cfgparse: warn when uid parameter is not a number

Currently, no warning are emitted when the uid is not a number.
Purpose of this warning is to let admins know they their configuration
won't be applied as expected.

(cherry picked from commit 79fee6aa7accf588b52c10155748f1d6de9d72ac)
(cherry picked from commit c7fba0137b1c823cf5041e030d77cdeb610291a8)
1 file changed