improvement for latest migration id calculation
diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php
index 3a1e7a0..ea46ce6 100644
--- a/system/libraries/Migration.php
+++ b/system/libraries/Migration.php
@@ -292,7 +292,7 @@
 
 		// Calculate the last migration step from existing migration
 		// filenames and procceed to the standard version migration
-		return $this->version((int) substr($last_migration, 0, 3));
+		return $this->version((int)$last_migration);
 	}
 
 	// --------------------------------------------------------------------