do not abort on failed directory reads

diff --cc bin/booh-classifier
index a3c6beb,b1789cb..5b4c69d
--- 1/bin/booh-classifier
--- 2/bin/booh-classifier
+++ b/bin/booh-classifier
@@@ -1281,9 -1286,11 +1285,13 @@@ def open_dir(*paths
                      msg 1, _("Ignoring directory %s, begins with a dot (indicating a hidden directory)") % dir
                      next
                  end
-                 entries += Dir.entries(dir).collect { |file| File.join(dir, file) }
+                 begin
+                     entries += Dir.entries(dir).collect { |file| File.join(dir, file) }
+                 rescue
+                     #- already puts'ed 10 lines upper
+                 end
 +                sb_msg(_("Scanning source directory... %s") % (_("%d entries found") % entries.size))
 +                Gtk.main_iteration while Gtk.events_pending?
              }
  
          else