Merge pull request #9869 from jakesmith/hpcc-17375

HPCC-17375 Fix misdeclared overriden method spotted by Coverity

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>

dali/base/dasds.cpp

@@ -2484,7 +2484,7 @@ public:
 
         clear(); // NB: *should* already be cleared, when tree is removed via removeTree
     }
-    virtual bool isEquivalent(IPropertyTree *tree) { return (NULL != QUERYINTERFACE(tree, CServerRemoteTree)); }
+    virtual bool isEquivalent(IPropertyTree *tree) const override { return (NULL != QUERYINTERFACE(tree, CServerRemoteTree)); }
 
     PDState processData(CServerConnection &connection, IPropertyTree &changeTree, MemoryBuffer &newIds);