Description: fix proxy request header vulnerability (httpoxy)
Origin: based on patch provided by Kurt Seifried

Index: apache2-2.4.12/server/util_script.c
===================================================================
--- apache2-2.4.12.orig/server/util_script.c	2016-07-14 08:38:24.893558792 -0400
+++ apache2-2.4.12/server/util_script.c	2016-07-14 08:38:24.893558792 -0400
@@ -191,6 +191,10 @@
             continue;
         }
 #endif
+        else if (!strcasecmp(hdrs[i].key, "Proxy")) {
+            /* Don't pass through HTTP_PROXY */
+            continue;
+        }
         else
             add_unless_null(e, http2env(r, hdrs[i].key), hdrs[i].val);
     }
