Disable update check by default

The updater compares against upstream CI builds, which is meaningless
for this fork. Manual check still works.

app/src/main/kotlin/com/hippo/ehviewer/Settings.kt

@@ -120,7 +120,7 @@ object Settings : DataStorePreferences(null) {
     // About
     val backupBeforeUpdate = boolPref("backup_before_update", false)
     val useCIUpdateChannel = boolPref("ci_update_channel", BuildConfig.SNAPSHOT)
-    val updateIntervalDays = intPref("update_interval_days", 7)
+    val updateIntervalDays = intPref("update_interval_days", 0)
 
     // Misc
     val languageFilter = intPref("language_filter", -1)