bibdocfile: fix handling of embargo firerole rule

• When bibdocfile is checking an document authorization the regular expression used to interpret the rule was wrong leading to rules such as:
  
  deny until '2010-01-01' allow any
  
  to be parsed as:
  
  deny until '2010-01-01'
  
  loosing the last line, and thus always denying access.
  
  This is now fixed. (closes #448)