lib: Add HttpBadRequestException

refs #9606

library/Icinga/Exception/Http/HttpBadRequestException.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace Icinga\Exception\Http;
+
+/**
+ * Exception thrown for sending a HTTP 400 response w/ a custom message
+ */
+class HttpBadRequestException extends HttpException
+{
+
+}