FIX: Remove referer check due to inconsistent browser behaviour
FIX: Remove referer check due to inconsistent browser behaviour

It seems that some browsers are now blocking full referer details,
so we are unsable to use this reliably.

jakerenzella/doubtfire-api,jakerenzella/doubtfire-api,jakerenzella/doubtfire-api,jakerenzella/doubtfire-api,doubtfire-lms/doubtfire-api,jakerenzella/doubtfire-api,doubtfire-lms/doubtfire-api,jakerenzella/doubtfire-api,doubtfire-lms/doubtfire-api,doubtfire-lms/doubtfire-api,jakerenzella/doubtfire-api,doubtfire-lms/doubtfire-api,doubtfire-lms/doubtfire-api,doubtfire-lms/doubtfire-api