sum remove on combine

Author: Baunsgaard

src/main/java/org/apache/sysds/runtime/compress/lib/CLALibCombineGroups.java

@@ -229,6 +229,8 @@ public static AColGroup combine(AColGroup a, AColGroup b, int nRow) {
 			ret = combineUC(combinedColumns, a, b);
 
 		try {
+			if(!CompressedMatrixBlock.debug)
+				return ret;
 			double sumCombined = ret.getSum(nRow);
 			double sumIndividualA = a.getSum(nRow);
 			double sumIndividualB = b.getSum(nRow);