Remove unnecessary db config of heroku
Remove unnecessary db config of heroku

hackmdio/hackmd,ironhack/hackmd,PeterDaveHello/hackmd,Yukaii/hackmd,Rwing/hackmd,PeterDaveHello/hackmd,jackycute/HackMD,ironhack/hackmd,hackmdio/hackmd,jccrofty30/hackmd,PeterDaveHello/hackmd,Yukaii/hackmd,ironhack/hackmd,aswathyjacob8/newtest,aswathyjacob8/newtest,Rwing/hackmd,hackmdio/hackmd,Rwing/hackmd,jackycute/HackMD,jccrofty30/hackmd,jackycute/HackMD,aswathyjacob8/newtest,Yukaii/hackmd,jccrofty30/hackmd