Cannot understand deprecation message recently added to Phobos

["Nordlöw" via Digitalmars-d-learn]

> https://github.com/D-Programming-Language/druntime/pull/825

I updated

https://github.com/nordlow/justd/blob/master/pprint.d

with two versions of shortDurationString(). DMD picks the right 
one using

static if (__VERSION__ >= 2066L)
     // new
else
     // old

I hope I it right this time.