models/login_source: add check for user for create/update on LDAP (#4405)
models/login_source: add check for user for create/update on LDAP (#4405)

* Add check for user for create/update

* Update login_source.go

* Update login_source.go

cgars/gogs,pikacloud/pikacode,dancewing/gogs,xaionaro/gogs,chriswatt/gogs,wangjild/gogs,cgars/gogs,mukaiu/gogs,dancewing/gogs,ForxaCoLab/forxa,xaionaro/gogs,ForxaCoLab/forxa,pikacloud/pikacode,chriswatt/gogs,mukaiu/gogs,gogits/gogs,dancewing/gogs,pikacloud/pikacode,mukaiu/gogs,dancewing/gogs,gogits/gogs,linquize/gogs,ForxaCoLab/forxa,cgars/gogs,wangjild/gogs,linquize/gogs,wangjild/gogs,xaionaro/gogs,gogits/gogs,chriswatt/gogs,linquize/gogs