src/mon/MonMap: modify dump function

src/mon/MonMap: modify dump function

Problem:
Current dump for "removed_ranks" and "disallowed_leaders"
doesn't have the correct format so the python test
script can parse through these values.

Solution:
Modified the values such that it is in the correct format

Signed-off-by: Kamoltat Sirivadhna <ksirivad@redhat.com>
(cherry picked from commit a7f3b7b749acabd235d615a3f5b80e3398a6d80d)