Remove Register button from right nav area
Remove Register button from right nav area

- This reduces our diff from upstream

Stanford-Online/edx-platform,jbassen/edx-platform,Stanford-Online/edx-platform,caesar2164/edx-platform,jbassen/edx-platform,caesar2164/edx-platform,jbassen/edx-platform,jbassen/edx-platform,Stanford-Online/edx-platform,caesar2164/edx-platform,jbassen/edx-platform,Stanford-Online/edx-platform,caesar2164/edx-platform