Don't let cutycapt hit localhost

fixes FOO-915

Change-Id: I3ef515869d4b338e85803c17d21aad1b5acaafc0
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/246594
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>

lib/cuty_capt.rb

@@ -37,7 +37,7 @@ class CutyCapt
   CUTYCAPT_DEFAULTS = {
     :delay => 3000,
     :timeout => 60000,
-    :ip_blacklist => [ '10.0.0.0/8', '172.16.0.0/12', '192.168.0.0/16', '169.254.169.254' ],
+    :ip_blacklist => [ '10.0.0.0/8', '172.16.0.0/12', '192.168.0.0/16', '169.254.169.254', '127.0.0.0/8' ],
     :domain_blacklist => [ ],
     :allowed_schemes => [ 'http', 'https' ],
     :lang => 'en,*;q=0.9'