Fix package names for servers

Author: katzj

source/tutorial/install-mongodb-on-redhat-centos-or-fedora-linux.txt

@@ -49,7 +49,7 @@ The 10gen repository contains four packages:
   optionally on other systems from which you may need to administer
   MongoDB systems.
 
-- ``mongo-server-10gen``
+- ``mongo-10gen-server``
 
   This package contains the :program:`mongod` and :program:`mongos`
   daemons from the latest **stable** release and associated
@@ -61,7 +61,7 @@ The 10gen repository contains four packages:
   this package on all production MongoDB hosts and optionally on other
   systems from which you may need to administer MongoDB systems.
 
-- ``mongo18-server-10gen``
+- ``mongo18-10gen-server``
 
   This package contains the :program:`mongod` and :program:`mongos`
   daemons from previous stable release and associated configuration and init