fixed correction of registrations

src/main/resources/templates/dashboard.html

@@ -77,7 +77,7 @@
 							<div class="card">
 								<div class="card-header">Teilnehmerdaten</div>
 								<div class="card-body">
-									<form th:action="@{/dashboard/update/}" th:object="${b}" method="post">
+									<form th:action="@{/dashboard/update}" th:object="${b}" method="post">
 										<input type="hidden" th:value="*{pk}" name="pk" />
 										<div class="container">
 											<div class="row mb-2">