[slime-devel] make swank safe if loaded into an image with an older version of swank in the image

hi, It can happen (though i admit it's a rare occurance) that you build an image with swank, update swank and then try to load swank into the existing image. hard to debug/understand errors ensue, this simple patch protects against that. -- -Marco Ring the bells that still can ring. Forget your perfect offering. There is a crack in everything. That's how the light gets in. -Leonard Cohen