[freeipa PR#4278][opened] Fix divide-by-zero when svc weight is 0 for all masters in location

[rcritten]

   URL: https://github.com/freeipa/freeipa/pull/4278
Author: rcritten
 Title: #4278: Fix divide-by-zero when svc weight is 0 for all masters in location
Action: opened

PR body:
"""
Fix div-by-zero when svc weight is 0 for all masters in location
    
The relative service weight output tries to show the relative
chance that any given master in a locaiton will be picked. This
didn't account for all masters having a weight of 0 which would
result in a divide-by-zero error.
    
Implement the following rules:
1. If all masters have weight == 0 then all are equally
   weighted.
2. If any masters have weight == 0 then they have an
   extremely small chance of being chosen, percentage is
   0.1.
3. Otherwise it's percentage change is based on the sum of
   the weights of non-zero masters.
    
https://pagure.io/freeipa/issue/8135
"""

To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/4278/head:pr4278
git checkout pr4278