only assign contributor role when user has no roles
only assign contributor role when user has no roles

ventoviro/forum,summerblue/phphub,ventoviro/forum,wyrover/phphub,summerblue/phphub,ventoviro/forum,wyrover/phphub,dut3062796s/phphub,dut3062796s/phphub,summerblue/phphub,wyrover/phphub,TimeFinger/earth-diary.org,TimeFinger/earth-diary.org,TimeFinger/earth-diary.org,dut3062796s/phphub