database parameters from free prop

src/AlarmHistoryTree.cpp

@@ -65,7 +65,9 @@ void AlarmHistoryTree::onFilterNameChanged(const QString &f) {
 
 void AlarmHistoryTree::onDbParamsReady(const CuData &p) {
     QString m;
-    if(p.B("err")) {
+    bool err;
+    p["err"].to<bool>(err);
+    if(err) {
         m = QuString(p, "msg");
         printf("AlarmHistoryTree::onDbParamsReady error ? %s\n", datos(p));
     }