Update vhost_apache.md

exploitation/vhost_apache.md

-Créer un vhost apache
+vhost apache
 ============================================
+
+# Behind proxy
+
+## allow ip
+
+    SetEnvIF X-Forwarded-For "89.87.169.5" AllowIPMaarch
+    SetEnvIF X-Forwarded-For "176.157.203.161" AllowIPMaarch
+    
+    <RequireAny>
+    	Require env AllowIPMaarch
+    </RequireAny>
+
+
+## foward info
+....
\ No newline at end of file