[IRCServices] is_voiced has a typo

[Andrew Church]

>in the function is_voiced in users.c it checks for CUMODE_o instead of 
>CUMODE_v

     This is already fixed for version 5.0; however, since it is not
actually used in version 4.5, I won't bother fixing it at this point.

  --Andrew Church
    achurch at achurch.org
    http://achurch.org/