Improve tea logout (#213)

fix message

fix lint

Impruve logout

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/213
Reviewed-by: Norwin <noerw@noreply.gitea.io>
Reviewed-by: techknowlogick <techknowlogick@gitea.io>

modules/config/login.go

@@ -184,6 +184,24 @@ func AddLogin(name, token, user, passwd, sshKey, giteaURL string, insecure bool)
 	return nil
 }
 
+// DeleteLogin delete a login by name
+func DeleteLogin(name string) error {
+	var idx = -1
+	for i, l := range Config.Logins {
+		if l.Name == name {
+			idx = i
+			break
+		}
+	}
+	if idx == -1 {
+		return fmt.Errorf("can not delete login '%s', does not exist", name)
+	}
+
+	Config.Logins = append(Config.Logins[:idx], Config.Logins[idx+1:]...)
+
+	return SaveConfig()
+}
+
 // GenerateLoginName generates a name string based on instance URL & adds username if the result is not unique
 func GenerateLoginName(url, user string) (string, error) {
 	parsedURL, err := utils.NormalizeURL(url)