Attempt to Divide by Zero in inflation.rs

[AurevoirXavier]

Thread 'main-tokio-12' panicked at 'attempt to divide by zero', /Users/xavier/Documents/program/darwinia/srml/staking/src/inflation.rs:26

[AurevoirXavier]

@hackfisher, line 26:

let maximum = maximum - maximum * 99_u128.pow(year.integer_sqrt()) / 100_u128.pow(year.integer_sqrt());

[AurevoirXavier]

Is this relate to #103?

Both of them happens at block-height 1000.

When I delete line 26, #103 disappeared.

[hackfisher]

@hackfisher, line 26:

let maximum = maximum - maximum * 99_u128.pow(year.integer_sqrt()) / 100_u128.pow(year.integer_sqrt());

I have no idea, this line related to inflation supply calculation(refer genepaper).

100_u128.pow(year.integer_sqrt()) It looks this value can not be zero, some tests might help

[AurevoirXavier]

Fixed: #133.