Rework server percentage check to remove 1 TODO

[Amemeda]

Removing // TODO check < 100 from line 234 of ConfigurableScanServerSelector.java

• if statement reworked to check server percentage instead of ratio, this way the TODO condition can be checked
• Added third condition to the if to make sure the computed percent is not infinite (NaN)
• server ratio computation was moved into new else clause

[Amemeda]

Removes 1 TODO from #2699

[Amemeda]

Working on test for NaN value on server percentage