Fix use-of-uninitialized-value (#15277)

Author: andrewstalin

ydb/public/lib/ydb_cli/commands/ydb_dynamic_config.h

@@ -101,7 +101,7 @@ class TCommandConfigVolatileDrop : public TYdbCommand {
     int Run(TConfig& config) override;
 
 private:
-    ui64 Version;
+    ui64 Version = 0;
     TString Cluster;
     THashSet<ui64> Ids;
     TString Dir;