Fix broken links iluwatar#915 (iluwatar#921)

Author: snehalatapandit

half-sync-half-async/README.md

@@ -27,11 +27,11 @@ Use Half-Sync/Half-Async pattern when
 
 ## Real world examples
 
-* [BSD Unix networking subsystem](http://www.cs.wustl.edu/~schmidt/PDF/PLoP-95.pdf)
+* [BSD Unix networking subsystem](https://www.dre.vanderbilt.edu/~schmidt/PDF/PLoP-95.pdf)
 * [Real Time CORBA](http://www.omg.org/news/meetings/workshops/presentations/realtime2001/4-3_Pyarali_thread-pool.pdf)
 * [Android AsyncTask framework](http://developer.android.com/reference/android/os/AsyncTask.html)
 
 ## Credits
 
-* [Douglas C. Schmidt and Charles D. Cranor - Half Sync/Half Async](http://www.cs.wustl.edu/~schmidt/PDF/PLoP-95.pdf)
+* [Douglas C. Schmidt and Charles D. Cranor - Half Sync/Half Async](https://www.dre.vanderbilt.edu/~schmidt/PDF/PLoP-95.pdf)
 * [Pattern Oriented Software Architecture Vol I-V](http://www.amazon.com/Pattern-Oriented-Software-Architecture-Volume-Patterns/dp/0471958697)

intercepting-filter/README.md

@@ -30,9 +30,8 @@ Use the Intercepting Filter pattern when
 ## Real world examples
 
 * [javax.servlet.FilterChain](https://tomcat.apache.org/tomcat-8.0-doc/servletapi/javax/servlet/FilterChain.html) and [javax.servlet.Filter](https://tomcat.apache.org/tomcat-8.0-doc/servletapi/javax/servlet/Filter.html)
-* [Struts 2 - Interceptors](https://struts.apache.org/docs/interceptors.html)
+* [Struts 2 - Interceptors](https://struts.apache.org/core-developers/interceptors.html)
 
 ## Credits
 
 * [TutorialsPoint - Intercepting Filter](http://www.tutorialspoint.com/design_pattern/intercepting_filter_pattern.htm)
-* [Presentation Tier Patterns](http://www.javagyan.com/tutorials/corej2eepatterns/presentation-tier-patterns)