bug: Fix roundup-admin security command. Lowercase optionalarg. Roles are indexed by lower case role name. So 'security User' and 'security user' should generate the same output. Also add testing for this case. Thread: https://sourceforge.net/p/roundup/mailman/roundup-users/thread/CAH-41398iTPhze7D_pZB8tqTBHF%3Dq6HYonbcG%2B%2BYN-ioDssXBw%40mail.gmail.com/#msg41557225 starting from: https://sourceforge.net/p/roundup/mailman/message/41557225/

def audit_html_files(db, cl, nodeid, newvalues):
    if 'type' in newvalues and newvalues['type'] == 'text/html':
        newvalues['type'] = 'text/plain'
    

def init(db):
    db.file.audit('set', audit_html_files)
    db.file.audit('create', audit_html_files)