Remove an assertion in DefaultReachedSet which was triggered after removing the initialState while the reachedSet was not empty. This may happen when the initialState gets merged during the CPAAlgorithm. In usual analyses this problem never occures, but in analyses with several states that get added to the reachedSet before the analysis (thus which state is the initial one is not important) this can happen. (This is currently only the case for the LiveVariablesAnalysis in function-wise configuration.)

git-svn-id: https://svn.sosy-lab.org/software/cpachecker/trunk@14628 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c