Fix database locking issue for setForcedUpgrade()

Due to an unclosed database

Author: Kisty

library/src/main/java/com/readystatesoftware/sqliteasset/SQLiteAssetHelper.java

@@ -179,6 +179,8 @@ public synchronized SQLiteDatabase getWritableDatabase() {
 
             // do force upgrade
             if (version != 0 && version < mForcedUpgradeVersion) {
+                //Close the old database
+                db.close();
                 db = createOrOpenDatabase(true);
                 db.setVersion(mNewVersion);
                 version = db.getVersion();