Update README.adoc

Typo leading 404 file

README.adoc

@@ -1,3 +1,3 @@
 image::https://github.com/spring-projects/spring-security-samples/workflows/CI/badge.svg[link=https://github.com/spring-projects/spring-security-samples/actions?query=workflow%3ACI]
 
-Samples for https://github.com/spring-projects/spring-security-
+Samples for https://github.com/spring-projects/spring-security