admin.erl: fix dialyzer warning
admin.erl: fix dialyzer warning

seyyed/scalaris,tectronics/scalaris,tectronics/scalaris,digshock/scalaris,tectronics/scalaris,seyyed/scalaris,digshock/scalaris,tectronics/scalaris,digshock/scalaris,seyyed/scalaris,seyyed/scalaris,seyyed/scalaris,seyyed/scalaris,digshock/scalaris,digshock/scalaris,tectronics/scalaris,seyyed/scalaris,digshock/scalaris,tectronics/scalaris,tectronics/scalaris,digshock/scalaris