Merge pull request #10281 from ghalliday/issue17956

HPCC-17956 Remove clang warning by deleting unnecessary virtuals

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>

system/jlib/jstats.cpp

@@ -953,11 +953,11 @@ public:
         in.read(value);
     }
 
-    virtual StatisticKind queryKind() const
+    StatisticKind queryKind() const
     {
         return kind;
     }
-    virtual unsigned __int64 queryValue() const
+    unsigned __int64 queryValue() const
     {
         return value;
     }