update cache key.

src/main/java/cn/com/qmth/examcloud/support/cache/CacheHelper.java

@@ -97,7 +97,7 @@ public class CacheHelper {
      * @return
      */
     public static BasePaperCacheBean getBasePaper(String paperId) {
-        return ObjectRedisCacheProcessor.get("Q_BASE_PAPER:", new Object[]{paperId},
+        return ObjectRedisCacheProcessor.get("Q_PAPER:BASE_", new Object[]{paperId},
                 BasePaperCacheBean.class, "EC-CORE-QUESTION",
                 "cn.com.qmth.examcloud.core.questions.service.cache.BasePaperCache");
     }