Reimplemented buildAfterCoarsen for only assembling vectors.

AMDiS/src/ProblemVec.cc

@@ -687,7 +687,7 @@ namespace AMDiS {
 	bool assembleMatrix = true;
 	// The DOFMatrix which should be assembled (or not, if assembleMatrix
 	// will be set to false).
-	DOFMatrix *matrix = (*systemMatrix)[i][j];
+	DOFMatrix *matrix = (asmMatrix ? (*systemMatrix)[i][j] : NULL);
 
 	if (writeAsmInfo && matrix) {
 	  for (std::vector<Operator*>::iterator it = matrix->getOperatorsBegin();