Added checking that the license file is a normal file, because otherwise an appropriately named directory crashes the license-checker through EISDIR, illegal operation on a directory.
Added checking that the license file is a normal file, because otherwise an appropriately named directory crashes the license-checker through EISDIR, illegal operation on a directory.

CantemoInternal/license-checker,pombredanne/license-checker,tmpvar/license-checker,StateFarmIns/license-checker,abtris/license-checker