Fixing cache store key typo
Fixing cache store key typo

Typo in line 19 led to cache misses and blew compilation times through the sky.
spodlecki/sprockets,daniel-rikowski/sprockets,jeremy/sprockets,askl56/sprockets,prathamesh-sonpatki/sprockets,Andreis13/sprockets,sferik/sprockets,eileencodes/sprockets,recursecenter/sprockets,rails/sprockets,guilleiguaran/sprockets,orlando/sprockets,bdezonia/sprockets,maclover7/sprockets,sideci-sample/sideci-sample-sprockets,kappezoro/sprockets,prusswan/sprockets,JuanitoFatas/sprockets,tricknotes/sprockets,masarakki/sprockets,schneems/sprockets,basecamp/sprockets,jcoyne/sprockets,byroot/sprockets