修改导出试卷结构不正确的 BUG

cqb-paper/src/main/java/com/qmth/cqb/paper/service/export/ExportPaperAbstractService.java

@@ -957,10 +957,10 @@ public abstract class ExportPaperAbstractService {
     	}
 		
 		//刷一遍number
+		int num = 0;
 		for(int i = 0;i<paperDetailExps.size();i++){
 			if(paperDetailExps.get(i).getSortNumber() == quesStructType.getId()){
 				List<PaperDetailUnitExp> exps = paperDetailExps.get(i).getPaperDetailUnits();
-				int num = 0;
 				for(int j = 0;j<exps.size();j++){
 					num++;
 					exps.get(j).setNumber(num);