Properly clear messages from database

app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt

@@ -989,12 +989,15 @@ fun Context.getFileSizeFromUri(uri: Uri): Long {
 // fix a glitch at enabling Release version minifying from 5.12.3
 // reset messages in 5.14.3 again, as PhoneNumber is no longer minified
 // reset messages in 5.19.1 again, as SimpleContact is no longer minified
-fun Context.clearAllMessagesIfNeeded() {
+fun Context.clearAllMessagesIfNeeded(callback: () -> Unit) {
     if (!config.wasDbCleared) {
         ensureBackgroundThread {
             messagesDB.deleteAll()
+            config.wasDbCleared = true
+            callback()
         }
-        config.wasDbCleared = true
+    } else {
+        callback()
     }
 }