Qt: Fix test for appending rows to UAT tables

We want to return with failure when the number of entries in
the row we're trying to append is greater than the number of
columns, not less than the number of rows in the table.

The IO Graph is the only place that uses appendEntry, and this
allows adding IO Graphs past the tenth graph.

Fix #18762

ui/qt/models/uat_model.cpp

@@ -239,8 +239,9 @@ int UatModel::columnCount(const QModelIndex &parent) const
 
 QModelIndex UatModel::appendEntry(QVariantList rowData)
 {
-    // A row with less entries could be added, where the remaining entries are empty
-    if (rowData.count() == 0 || rowData.count() < rowCount())
+    // Don't add an empty row, or a row with more entries than we have columns,
+    // but a row with fewer can be added, where the remaining entries are empty
+    if (rowData.count() == 0 || rowData.count() > columnCount())
         return QModelIndex();
 
     QModelIndex newIndex;