fix infinite loop bug by unsetting parent when card is discarded
fix infinite loop bug by unsetting parent when card is discarded

gryffon/ringteki,gryffon/ringteki,DukeTax/throneteki,Antaiseito/throneteki_for_doomtown,cryogen/gameteki,jbrz/throneteki,jbrz/throneteki,cavnak/throneteki,Antaiseito/throneteki_for_doomtown,ystros/throneteki,samuellinde/throneteki,cavnak/throneteki,jeremylarner/ringteki,samuellinde/throneteki,gryffon/ringteki,cryogen/throneteki,jeremylarner/ringteki,cryogen/throneteki,DukeTax/throneteki,jeremylarner/ringteki,cryogen/gameteki