What does isoidemo iikoto naiyo mean?

I've tried looking for a translation, but I can't find one.

According to the Google translation,
It is not a good thing even in a hurry.
急いでも良いことないよ
いそいでもいいことないよ

It means "even if you hurry, that is no good/use," with the connotation of "just rushing (for the sake of it) is going to get you to a no better position, rather you could make things worse."

It might be a little deviate story but, in Japan and there is a saying, "More haste, less speed（isogaba maware,急がば回れ）".
（If you hurry, take a long but steady road.）
Seiteha kotowo shisonjiru(急いてはことを仕損じる）, there is also a saying.
（You will fail if you hurry too much.）
In the English proverb,
Haste makes waste.
More haste, less speed.
Make haste slowly.
It seems to be similar to.
http://www.geocities.jp/sonny_l_lab/english/proverbs/h/haste_makes.htm

It simply means "slow down".