Remove known issues section for 2.11.4

As we will postpone the release for tomorrow, the bug will
be fixed in the release.
Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Hrvoje Ribicic <riba@google.com>

NEWS

@@ -25,14 +25,6 @@ Inherited from the 2.9 branch:
 
 - Make ganeti-cleaner switch to save working directory (Issue 880)
 
-Known issues
-~~~~~~~~~~~~
-
-The following issue is present in this release and will be fixed before
-the next release.
-
-- Issue 889: Unhandled Xen state '-------'
-
 
 Version 2.11.3
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