Apply PR #3940 to sqlite3 driver and fix a wrong var name
diff --git a/system/database/drivers/sqlite3/sqlite3_forge.php b/system/database/drivers/sqlite3/sqlite3_forge.php
index 69f65b6..24690ba 100644
--- a/system/database/drivers/sqlite3/sqlite3_forge.php
+++ b/system/database/drivers/sqlite3/sqlite3_forge.php
@@ -74,7 +74,8 @@
 
 		if (version_compare($this->db->version(), '3.3', '<'))
 		{
-			$this->create_table_if = FALSE;
+			$this->_create_table_if = FALSE;
+			$this->_drop_table_if   = FALSE;
 		}
 	}