Fix wording error

Author: jaredly

source/tutorial/install-mongodb-on-ubuntu.txt

@@ -23,7 +23,7 @@ configuration and operation.
 .. note:: 
 
    If you use an older Ubuntu that does **not** use Upstart, (i.e. any
-   since version 9.10 "Karmic,") please follow the instructions on the
+   version before 9.10 "Karmic") please follow the instructions on the
    :doc:`install-mongodb-on-debian` tutorial.
 
 .. seealso:: The documentation of following related processes and