Remove stray quotation mark from courseware-error text.

lms/templates/courseware/courseware-error.html

@@ -20,7 +20,7 @@
     </h1>
     <p>
       ${_("We're sorry, this module is temporarily unavailable. Our staff is working to fix "
-      "it as soon as possible. Please email us at {tech_support_email}' to report any problems or downtime.").format(
+      "it as soon as possible. Please email us at {tech_support_email} to report any problems or downtime.").format(
       tech_support_email=u'<a href=\"mailto:{0}\">{0}</a>'.format(settings.TECH_SUPPORT_EMAIL)
       )}
     </p>