Configure a real retry minimum of 1s

[konstin]

By default, retry-policies compute the actual retry duration as min_retry_interval * (base ** n_past_retries) * rng.uniform(0.0, 1.0), so the first sleep duration would be between 0s and 1s. This change bumps this to a real 1s minimum.

[zsol]

so for a given $d$ duration and $m$ minimum retry bound, the jitter application gives us $(d - {m\over{2}}) j + {m\over{2}}$ seconds (where $0 < j < 1$), so with $m=2$ and $d_1=2$, $d_2=4$, $d_3=8$ our actual retry delays will be $j+1$, $3j+1$, and $7j+1$, which are between $(1,2)$, $(1,4)$, and $(1,8)$ respectively. Is that what we want?

[konstin]

I'm not convinced by any Jitter option, but those values is better than the ones we currently have.

[zsol]

if yes, then this looks good to me.