Replace TODO comment with Issue ticket changing RedisAccessor to abstract.

See spring-projects#2494
See spring-projects#2493

Author: jxblum

src/main/java/org/springframework/data/redis/core/RedisAccessor.java

@@ -29,7 +29,6 @@
  * @author Costin Leau
  * @author John Blum
  * @see org.springframework.beans.factory.InitializingBean
- * TODO: Declare as abstract
  */
 public class RedisAccessor implements InitializingBean {