wwwroot will be autogenerated on every page load if it is not set in the config
file. There are some implications of storing it in the database, it particular
it affects the hostname and protocol changes. Since its autogeneration takes
just 2ms there is no much sense keeping it in the database.

Change-Id: I7c08539c6ad4e4c5fba819a459b7f60bb1d9741e
Signed-off-by: Ruslan Kabalin <ruslan.kabalin@luns.net.uk>