Cleanup ignored_list_T110.txt

This commit removes "ignored_list_T110.txt". The last entry was
already moved to tempest.lib[0]. So we can remove this file finally.

[0] Ia9aeab78e530c798dfa7b7d6f71e4b3ea3a84b7f

Change-Id: Icfa511c2874da7135d8971471d95892dfbf07882
diff --git a/tempest/hacking/ignored_list_T110.txt b/tempest/hacking/ignored_list_T110.txt
deleted file mode 100644
index 0e7e894..0000000
--- a/tempest/hacking/ignored_list_T110.txt
+++ /dev/null
@@ -1 +0,0 @@
-./tempest/services/object_storage/object_client.py