Restore: .gitignore changes for 19bef0e

git-svn-id: https://develop.svn.wordpress.org/branches/fixes-64393-restore-version-history@62139 602fd350-edb4-49c9-b593-d223f7449a82

Author: dmsnell

.gitignore

@@ -33,6 +33,7 @@ wp-tests-config.php
 /src/wp-admin/css/colors/*/*.css
 /src/wp-admin/js
 /src/wp-includes/assets/*
+!/src/wp-includes/assets/icon-library-manifest.php
 !/src/wp-includes/assets/script-loader-packages.php
 !/src/wp-includes/assets/script-modules-packages.php
 /src/wp-includes/js