Fix migration script of revision lacks of definition of primary key
Fix migration script of revision lacks of definition of primary key

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