HBASE-25300 'Unknown table hbase:quota' happens when desc table in shell if quota disabled (#2673)

Signed-off-by: Guanghao Zhang <zghao@apache.org>
Signed-off-by: Pankaj Kumar<pankajkumar@apache.org>

hbase-shell/src/main/ruby/shell/commands/describe.rb

@@ -44,6 +44,7 @@ EOF
           puts
         end
         formatter.footer
+        if admin.exists?(::HBaseQuotasConstants::QUOTA_TABLE_NAME.to_s)
           if table.to_s != 'hbase:meta'
             # No QUOTAS if hbase:meta table
             puts
@@ -53,6 +54,9 @@ EOF
             end
             formatter.footer(count)
           end
+        else
+          puts 'Quota is disabled'
+        end
       end
       # rubocop:enable Metrics/AbcSize, Metrics/MethodLength
     end