Added check for bigbluebutton/ for endpoint config (#408)

config/application.rb

@@ -56,6 +56,9 @@ module Greenlight
     config.bigbluebutton_secret = ENV["BIGBLUEBUTTON_SECRET"] || config.bigbluebutton_secret_default
 
     # Fix endpoint format if required.
+    config.bigbluebutton_endpoint += "/" unless config.bigbluebutton_endpoint.ends_with?('/')
+    config.bigbluebutton_endpoint +=
+      "bigbluebutton/api/" unless config.bigbluebutton_endpoint.ends_with?('bigbluebutton/api/')
     config.bigbluebutton_endpoint += "api/" unless config.bigbluebutton_endpoint.ends_with?('api/')
 
     if config.loadbalanced_configuration