Remove LDAP 3rd party starter reference

Spring Boot provides now a LDAP starter based on this work so this
reference is no longer needed.

spring-boot-starters/README.adoc

@@ -106,9 +106,6 @@ do as they were designed before this was clarified.
 | https://cxf.apache.org/docs/springboot.html[Apache CXF]
 | https://github.com/apache/cxf
 
-| LDAP
-| https://github.com/eddumelendez/ldap-spring-boot
-
 | http://infinispan.org/[Infinispan]
 | https://github.com/infinispan/infinispan-spring-boot