fix comment bug: minium db mmapSize is 1MB instead of 4MB
fix comment bug: minium db mmapSize is 1MB instead of 4MB

nilslice/bolt,linearregression/bolt,xuzhaokui/bolt,hvnsweeting/bolt,cep21/bolt,lmars/bolt,brahmaroutu/bolt,ngaut/bolt,yew011/bolt,pspeter3/bolt,raggi/bolt,chlorm-forks/bolt,boltdb/bolt,odeke-em/bolt,btcsuite/bolt,li-ang/bolt,wyzssw/bolt,etcd-io/bbolt,pombredanne/bolt-2,mr-justin/bolt,jmptrader/bolt,benbjohnson/bolt,mashuai/bolt,dindinet/bolt-1,conseweb/bolt,Compasses/bolt,tvmaly/bolt,samanalysis/bolt,jefby/bolt,tv42/bolt,joyrexus/bolt,Apsalar/bolt