gui, lib/config: Add GUI user and password notification (fixes #4703) (#6536)

lib/config/migrations.go

@@ -25,6 +25,7 @@ import (
 // update the config version. The order of migrations doesn't matter here,
 // put the newest on top for readability.
 var migrations = migrationSet{
+	{31, migrateToConfigV31},
 	{30, migrateToConfigV30},
 	{29, migrateToConfigV29},
 	{28, migrateToConfigV28},
@@ -85,6 +86,11 @@ func (m migration) apply(cfg *Configuration) {
 	cfg.Version = m.targetVersion
 }
 
+func migrateToConfigV31(cfg *Configuration) {
+	// Show a notification about setting User and Password
+	cfg.Options.UnackedNotificationIDs = append(cfg.Options.UnackedNotificationIDs, "authenticationUserAndPassword")
+}
+
 func migrateToConfigV30(cfg *Configuration) {
 	// The "max concurrent scans" option is now spelled "max folder concurrency"
 	// to be more general.