Fix toggletag

awful.client.toggletag assumes that the tags array is indexed by tag
objects. This appears to not be the case after v3.2-31-g6430738, when
client objects stopped using otables. This patch makes toggletag iterate
through the client tag array till it finds the entry to remove,
otherwise it appends the new entry at the end.

Signed-off-by: Nikos Ntarmos <ntarmos@cs.uoi.gr>
Signed-off-by: Julien Danjou <julien@danjou.info>

lib/awful/client.lua.in

@@ -443,12 +443,19 @@ function toggletag(target, c)
     -- Check that tag and client screen are identical
     if sel and sel.screen == target.screen then
         local tags = sel:tags()
-        if tags[target] then
+        local index = nil;
+        for i, v in ipairs(tags) do
+            if v == target then
+                index = i
+                break
+            end
+        end
+        if index then
             -- If it's the only tag for the window, stop.
             if #tags == 1 then return end
-            tags[tags[target]] = nil
+            tags[index] = nil
         else
-            tags[target] = target
+            tags[#tags + 1] = target
         end
         sel:tags(tags)
     end