Roundcube failregex -- anchor at the beginning as well

2 unrelated commits -- if needed, could split into separate PRs since we might need to boil roundcube more

logging: never enough ;) but now it should be easier to work on regexes

roundcube:

- I wonder if we are not maldetecting the date/time since we are not capturing timezone offset in our datedetected?

- if we get no more log lines, this one might be too conservative