Fix test and model

Author: egregius313

csharp/ql/lib/ext/Dapper.model.yml

@@ -108,4 +108,4 @@ extensions:
       pack: codeql/csharp-all
       extensible: summaryModel
     data:
-      - ["Dapper", "SqlMapper", False, "AsList<T>", "(System.Collections.Generic.IEnumerable<T>)", "", "Argument[0].WithElement", "ReturnValue", "taint", "manual"]
+      - ["Dapper", "SqlMapper", False, "AsList<T>", "(System.Collections.Generic.IEnumerable<T>)", "", "Argument[0].Element", "ReturnValue.Element", "taint", "manual"]

csharp/ql/test/library-tests/dataflow/flowsources/stored/database/dapper/UseDapper.cs

@@ -41,7 +41,7 @@ public static void Bad04(string connectionString, string query)
             using (var connection = new SqlConnection(connectionString))
             {
                 var results = connection.Query<object>(query).AsList();
-                Sink(results); // $ hasTaintFlow=line:43
+                Sink(results[0]); // $ hasTaintFlow=line:43
             }
         }