I really have not heard of such original proverb. But there is one really close, but it is a funny modern phrase, used in southern China or Hong Kong:
if the business (such as a mom and pop grocery store) is so low, we may as well play some mahjong or do a little bit of gambling
but this is the closest one I can think of, similar to ...
There is a saying: "一不做，二不休"(either don't do or don't stop).
It means "Either not doing it, or see it through to the end once you started"
In other words: "If you are not ready to finish what you started (too slow to finish), then don't do it (stop)"
Maybe it is the origin of this translated proverb