Do not show update notification for "TWRP A/B Retention script" module (Fix #187)

app/src/main/java/com/fox2code/mmm/background/BackgroundUpdateChecker.java

@@ -57,6 +57,7 @@ public class BackgroundUpdateChecker extends Worker {
         int moduleUpdateCount = 0;
         for (LocalModuleInfo localModuleInfo :
                 ModuleManager.getINSTANCE().getModules().values()) {
+            if ("twrp-keep".equals(localModuleInfo.id)) continue;
             RepoModule repoModule = RepoManager.getINSTANCE()
                     .getModules().get(localModuleInfo.id);
             localModuleInfo.checkModuleUpdate();