EDX-433: Delete period in course_about.
EDX-433: Delete period in course_about.

yokose-ks/edx-platform,yokose-ks/edx-platform,yokose-ks/edx-platform,WatanabeYasumasa/edx-platform,yokose-ks/edx-platform,WatanabeYasumasa/edx-platform,WatanabeYasumasa/edx-platform,WatanabeYasumasa/edx-platform,yokose-ks/edx-platform