Removed "Register book" link from OpenDSA navigation menu.
Removed "Register book" link from OpenDSA navigation menu.

RJFreund/OpenDSA,RJFreund/OpenDSA,hosamshahin/OpenDSA,hosamshahin/OpenDSA,hosamshahin/OpenDSA,hosamshahin/OpenDSA,RJFreund/OpenDSA,hosamshahin/OpenDSA,RJFreund/OpenDSA,hosamshahin/OpenDSA,RJFreund/OpenDSA,hosamshahin/OpenDSA,hosamshahin/OpenDSA,hosamshahin/OpenDSA,RJFreund/OpenDSA,RJFreund/OpenDSA,RJFreund/OpenDSA