Fix profiler trying to serialize invalid utf8
Fix profiler trying to serialize invalid utf8

The cookie value contains invalid utf8 characters most of the time so
let's just ignore it as it is also not that interesting to analyse.

Signed-off-by: Carl Schwan <de187642e6c75f60d10f29e52cab54cdf676870d@carlschwan.eu>

nextcloud/server,nextcloud/server,nextcloud/server,nextcloud/server