Modified the assertion to fix a crash.
Modified the assertion to fix a crash.

The crash only happened in release mode.

shlomif/black-hole-solitaire,shlomif/black-hole-solitaire,shlomif/black-hole-solitaire,shlomif/black-hole-solitaire,shlomif/black-hole-solitaire,shlomif/black-hole-solitaire