Change username validation to not use @ and +
Change username validation to not use @ and +

dayatz/taiga-back,obimod/taiga-back,joshisa/taiga-back,gauravjns/taiga-back,frt-arch/taiga-back,dayatz/taiga-back,seanchen/taiga-back,joshisa/taiga-back,taigaio/taiga-back,coopsource/taiga-back,bdang2012/taiga-back-casting,jeffdwyatt/taiga-back,Zaneh-/bearded-tribble-back,CoolCloud/taiga-back,Rademade/taiga-back,EvgeneOskin/taiga-back,CMLL/taiga-back,WALR/taiga-back,crr0004/taiga-back,gam-phon/taiga-back,CoolCloud/taiga-back,astronaut1712/taiga-back,gam-phon/taiga-back,CMLL/taiga-back,CMLL/taiga-back,forging2012/taiga-back,rajiteh/taiga-back,coopsource/taiga-back,rajiteh/taiga-back,Zaneh-/bearded-tribble-back,rajiteh/taiga-back,WALR/taiga-back,obimod/taiga-back,Tigerwhit4/taiga-back,bdang2012/taiga-back-casting,xdevelsistemas/taiga-back-community,jeffdwyatt/taiga-back,dycodedev/taiga-back,jeffdwyatt/taiga-back,Zaneh-/bearded-tribble-back,seanchen/taiga-back,taigaio/taiga-back,WALR/taiga-back,WALR/taiga-back,crr0004/taiga-back,bdang2012/taiga-back-casting,forging2012/taiga-back,gauravjns/taiga-back,CoolCloud/taiga-back,CMLL/taiga-back,gauravjns/taiga-back,Rademade/taiga-back,taigaio/taiga-back,dycodedev/taiga-back,astronaut1712/taiga-back,gam-phon/taiga-back,gauravjns/taiga-back,bdang2012/taiga-back-casting,astronaut1712/taiga-back,frt-arch/taiga-back,EvgeneOskin/taiga-back,obimod/taiga-back,coopsource/taiga-back,astagi/taiga-back,forging2012/taiga-back,astagi/taiga-back,dayatz/taiga-back,joshisa/taiga-back,19kestier/taiga-back,EvgeneOskin/taiga-back,joshisa/taiga-back,CoolCloud/taiga-back,crr0004/taiga-back,Tigerwhit4/taiga-back,EvgeneOskin/taiga-back,Rademade/taiga-back,xdevelsistemas/taiga-back-community,Rademade/taiga-back,rajiteh/taiga-back,frt-arch/taiga-back,Tigerwhit4/taiga-back,19kestier/taiga-back,dycodedev/taiga-back,dycodedev/taiga-back,crr0004/taiga-back,forging2012/taiga-back,coopsource/taiga-back,seanchen/taiga-back,Tigerwhit4/taiga-back,xdevelsistemas/taiga-back-community,astronaut1712/taiga-back,jeffdwyatt/taiga-back,19kestier/taiga-back,gam-phon/taiga-back,astagi/taiga-back,seanchen/taiga-back,Rademade/taiga-back,obimod/taiga-back,astagi/taiga-back