anaconda: mark anaconda-tb as editable file and remove rootpw lines

anaconda-tb file contains the main information about Anaconda problems.

report-gtk won't be highlighting forbidden words, because anaconda-tb
contains many false positives words as the file is mainly composed of
log outputs.

Related to #1041558

Signed-off-by: Jakub Filak <jfilak@redhat.com>