Nimble Disallow Version

[fengkehh]

I built a library using Weave which is currently incompatible with nim 1.4.6 
currently. As such I have specified in its nimble file:
    
    
    requires nim >= 1.4
    requires nim < 1.4.6
    
    
    Run

Turns out problem with Weave was fixed in the current 1.5.1 devel past 
04/30/2021. So right now I'd like to specifically blacklist Nim 1.4.6 but allow 
anything else past 1.4. Is there a way to do this in the nimble file? I've 
tried `requires nim != 1.4.6` already and it doesn't seem to work.