Revert "org.apache.httpcomponents upgrade (#6)"

This reverts commit 9bf3d4b17de971a0074624732c5fb4699cbc74e0.
diff --git a/pom.xml b/pom.xml
index ea89273..55104c9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -365,12 +365,12 @@
     <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpcore</artifactId>
-      <version>4.4.13</version>
+      <version>4.2.3</version>
     </dependency>
     <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpclient</artifactId>
-      <version>4.5.11</version>
+      <version>4.2.3</version>
     </dependency>
 
     <!-- for rss feed generation -->