Update prepare.st for Squeak-trunk
Update prepare.st for Squeak-trunk

The MCMcmUpdater API has changed.

hpi-swa/smalltalkCI,peteruhnak/smalltalkCI,fniephaus/filetreeCI,hpi-swa/filetreeCI,hpi-swa/filetreeCI,fniephaus/filetreeCI,peteruhnak/smalltalkCI,hpi-swa/smalltalkCI,dalehenrich/smalltalkCI,dalehenrich/smalltalkCI,dalehenrich/smalltalkCI,fniephaus/filetreeCI,hpi-swa/filetreeCI,peteruhnak/smalltalkCI