修改导入试卷，试题属性为空不能导入的bug

cqb-paper/src/main/java/com/qmth/cqb/paper/service/ImportPaperService.java

@@ -882,7 +882,7 @@ public class ImportPaperService {
 			}
 		}
 		//一级属性有值，二级属性为空
-		else {
+		else if(StringUtils.isNotBlank(firstProperty) && StringUtils.isBlank(secondProperty)){
 			//根据课程查询所有课程属性树
 			List<CourseProperty> courseProperties = coursePropertyRepo.findByCourseCode(paper.getCourse().getCode());
 			if(courseProperties == null || courseProperties.size()<1){
@@ -915,6 +915,9 @@ public class ImportPaperService {
 		    		throw new PaperException(importPaperCheck.errorInfo);
 				}
 			}
+		}//一级，二级都为空
+		else {
+			
 		}
 	}