should_disable_dir_fetches() now returns 1 if DisableNetwork==1

This change prevents LD_BUG warnings and bootstrap failure messages
when we try to do directory fetches when starting with
DisableNetwork == 1, a consensus present, but no descriptors (or
insufficient descriptors) yet.

Fixes bug 11200 and bug 10405.  It's a bugfix on 0.2.3.9-alpha.
Thanks to mcs for walking me through the repro instructions!

changes/bug11200

@@ -0,0 +1,5 @@
+  - Minor bugfixes:
+
+    - Avoid generating spurious warnings and failure messages when
+      starting with DisableNetwork enabled. Fixes bug 11200 and bug
+      10405; bugfix on 0.2.3.9-alpha.

src/or/networkstatus.c

@@ -898,6 +898,14 @@ should_delay_dir_fetches(const or_options_t *options, const char **msg_out)
     *msg_out = NULL;
   }
 
+  if (options->DisableNetwork) {
+    if (msg_out) {
+      *msg_out = "DisableNetwork is set.";
+    }
+    log_info(LD_DIR, "Delaying dir fetches (DisableNetwork is set)");
+    return 1;
+  }
+
   if (options->UseBridges) {
     if (!any_bridge_descriptors_known()) {
       if (msg_out) {