Update README.md with new 401_STABLE branch.

Author: danmarsden

README.md

@@ -71,7 +71,7 @@ Features not yet implemented:
 | Moodle 5.0        | `MOODLE_500_STABLE`| 8.2+      | v2.3.7        |
 | Moodle 4.5        | `MOODLE_405_STABLE`| 8.1+      | v2.3.7        |
 | Moodle 4.4        | `MOODLE_404_STABLE`| 8.1+      | v2.3.5        |
-| Moodle 3.9 to 4.3 | `MOODLE_39_STABLE` | 7.4+      | v2.0.5        |
+| Moodle 4.1 to 4.3 | `MOODLE_401_STABLE`| 7.4+      | v2.0.5        |
 | Totara 19+        | `TOTARA_19`        | 7.4+      | v2.0.5        |
 | Totara 13+        | `TOTARA_13_STABLE` | 7.4+      | v2.0.5        |