pac4j expects to replace in setResponseHeader

This fixes a bug with central logout where the location header
was set twice for example.

src/main/java/org/pac4j/jax/rs/pac4j/JaxRsContext.java

@@ -84,6 +84,8 @@ public void setResponseStatus(int code) {
 
     @Override
     public void setResponseHeader(String name, String value) {
+        // header() adds headers, so we must remove the previous value first
+        getAbortBuilder().header(name, null);
         getAbortBuilder().header(name, value);
     }