headscale: generage random suffix for new users (#132)

Change-Id: I7ef50ca45d005592bcd627920e4512ba876ca6b7

Co-authored-by: Giorgi Lekveishvili <lekva@gl-mbp-m1-max.local>
diff --git a/core/installer/welcome/welcome.go b/core/installer/welcome/welcome.go
index eb7a2dc..9411747 100644
--- a/core/installer/welcome/welcome.go
+++ b/core/installer/welcome/welcome.go
@@ -215,7 +215,7 @@
 			return
 		}
 		nsGen := installer.NewPrefixGenerator(config.Values.NamespacePrefix)
-		suffixGen := installer.NewEmptySuffixGenerator()
+		suffixGen := installer.NewFixedLengthRandomSuffixGenerator(3)
 		appManager, err := installer.NewAppManager(s.repo, s.nsCreator)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)