Check that buttons exist before comparing length (#1353)
Check that buttons exist before comparing length (#1353)

Fixes THRONETEKI-19M
Fixes THRONETEKI-19P
Fixes THRONETEKI-19Q
Fixes THRONETEKI-19R
Fixes THRONETEKI-19S
cryogen/gameteki,Antaiseito/throneteki_for_doomtown,cryogen/throneteki,ystros/throneteki,Antaiseito/throneteki_for_doomtown,DukeTax/throneteki,cryogen/throneteki,DukeTax/throneteki,cryogen/gameteki