Fix index.html: SBA.csrf must not be undefined

Author: joshiste

spring-boot-admin-server-ui/src/main/frontend/index.html

@@ -47,12 +47,10 @@
  uiSettings: /*[[${uiSettings}]]*/ {},
  user: /*[[${user}]]*/ null,
  extensions: [],
- /*[#th:block th:if="${_csrf}"]*/
  csrf: {
- parameterName: /*[[${_csrf.parameterName}]]*/ null,
- headerName: /*[[${_csrf.headerName}]]*/ null
+ parameterName: /*[[${_csrf} ? ${_csrf.parameterName} : 'null']]*/ null,
+ headerName: /*[[${_csrf} ? ${_csrf.headerName} : 'null']]*/ null
  },
- /*[/th:block]*/
  use: function (ext) {
  this.extensions.push(ext);
  }