Authorities also advertise caches-extra-info

(Whoops, thought I had committed this before)

Improvement to 11683 fix. Based on patch from Karsten.

changes/bug11683

@@ -3,4 +3,6 @@
       documents, regardless of whether their server descriptor contains a
       "caches-extra-info" line or not. Fixes part of #11683. Bugfix on
       0.2.0.1-alpha.
-
+    - When running as a v3 directory authority, advertise that you serve
+      extra-info documents so that clients who want them can find them from
+      you too. Fixes part of bug #11683. Bugfix on 0.2.0.1-alpha.

src/or/router.c

@@ -2371,7 +2371,8 @@ router_dump_router_to_string(routerinfo_t *router,
     has_extra_info_digest ? "extra-info-digest " : "",
     has_extra_info_digest ? extra_info_digest : "",
     has_extra_info_digest ? "\n" : "",
-    options->DownloadExtraInfo ? "caches-extra-info\n" : "",
+    (options->DownloadExtraInfo || options->V3AuthoritativeDir) ?
+                         "caches-extra-info\n" : "",
     onion_pkey, identity_pkey,
     family_line,
     we_are_hibernating() ? "hibernating 1\n" : "",