updated header active tab border color
updated header active tab border color

(cherry picked from commit d7ab8327cb6cb1f08fd5e0a71a616fef188a628e)

gymnasium/edx-platform,appsembler/edx-platform,appsembler/edx-platform,kmoocdev2/edx-platform,CredoReference/edx-platform,CredoReference/edx-platform,gsehub/edx-platform,gsehub/edx-platform,gymnasium/edx-platform,kmoocdev2/edx-platform,Edraak/edraak-platform,gymnasium/edx-platform,BehavioralInsightsTeam/edx-platform,kmoocdev2/edx-platform,appsembler/edx-platform,appsembler/edx-platform,BehavioralInsightsTeam/edx-platform,kmoocdev2/edx-platform,Stanford-Online/edx-platform,Stanford-Online/edx-platform,CredoReference/edx-platform,Edraak/edraak-platform,Edraak/edraak-platform,kmoocdev2/edx-platform,gsehub/edx-platform,BehavioralInsightsTeam/edx-platform,Edraak/edraak-platform,CredoReference/edx-platform,Stanford-Online/edx-platform,BehavioralInsightsTeam/edx-platform,Stanford-Online/edx-platform,gsehub/edx-platform,gymnasium/edx-platform