fix checkmating in conditional premoves - closes #978
fix checkmating in conditional premoves - closes #978

clarkerubber/lila,JimmyMow/lila,arex1337/lila,arex1337/lila,Unihedro/lila,luanlv/lila,terokinnunen/lila,TangentialAlan/lila,arex1337/lila,terokinnunen/lila,TangentialAlan/lila,samuel-soubeyran/lila,samuel-soubeyran/lila,JimmyMow/lila,TangentialAlan/lila,r0k3/lila,arex1337/lila,Unihedro/lila,clarkerubber/lila,r0k3/lila,arex1337/lila,Unihedro/lila,JimmyMow/lila,arex1337/lila,TangentialAlan/lila,luanlv/lila,Unihedro/lila,luanlv/lila,r0k3/lila,luanlv/lila,Unihedro/lila,terokinnunen/lila,r0k3/lila,terokinnunen/lila,luanlv/lila,arex1337/lila,JimmyMow/lila,JimmyMow/lila,terokinnunen/lila,TangentialAlan/lila,JimmyMow/lila,Unihedro/lila,samuel-soubeyran/lila,samuel-soubeyran/lila,JimmyMow/lila,luanlv/lila,clarkerubber/lila,clarkerubber/lila,clarkerubber/lila,samuel-soubeyran/lila,luanlv/lila,TangentialAlan/lila,terokinnunen/lila,clarkerubber/lila,clarkerubber/lila,r0k3/lila,Unihedro/lila,r0k3/lila,r0k3/lila,terokinnunen/lila,samuel-soubeyran/lila,samuel-soubeyran/lila,TangentialAlan/lila