Fix slide might not provide slideOptions meta
Fix slide might not provide slideOptions meta

PeterDaveHello/hackmd,jackycute/HackMD,ironhack/hackmd,Yukaii/hackmd,hackmdio/hackmd,ironhack/hackmd,hackmdio/hackmd,hackmdio/hackmd,PeterDaveHello/hackmd,PeterDaveHello/hackmd,jackycute/HackMD,Yukaii/hackmd,jackycute/HackMD,Yukaii/hackmd,ironhack/hackmd,Rwing/hackmd,Rwing/hackmd,Rwing/hackmd