Update serv.go (#7822)

small semantics fix
"Hi there, user!" looks better than "Hi there: user!"

cmd/serv.go

@@ -109,7 +109,7 @@ func runServ(c *cli.Context) error {
 		if key.Type == models.KeyTypeDeploy {
 			println("Hi there! You've successfully authenticated with the deploy key named " + key.Name + ", but Gitea does not provide shell access.")
 		} else {
-			println("Hi there: " + user.Name + "! You've successfully authenticated with the key named " + key.Name + ", but Gitea does not provide shell access.")
+			println("Hi there, " + user.Name + "! You've successfully authenticated with the key named " + key.Name + ", but Gitea does not provide shell access.")
 		}
 		println("If this is unexpected, please log in with password and setup Gitea under another user.")
 		return nil