ensure user slug unicity, fixes #1213
ensure user slug unicity, fixes #1213

Discordius/Telescope,Discordius/Telescope,Discordius/Telescope,Discordius/Lesswrong2,Discordius/Telescope,Discordius/Lesswrong2,Discordius/Lesswrong2,Discordius/Lesswrong2