remove leading space from restrict file

[ImanHosseini]

If the file is named "a.out" the restrict file would not work correctly because the regex does not skip whitespaces and would match " a.out" which is not equal to "a.out". So there should be either no leading spaces or the regex be changed to skip leading -and also trailing would be nice- whitespaces)

[bharadwajy]

Thanks for the PR.

I pushed a fix (ce6706eb8116e5cae2d0099b989ca8ae55c7c77d) to address the limitation you identified. Thus this change is no longer needed. Hence closing the PR.

Feel free to report any bugs you might encounter.