Fix configuring source path globs that expand into a single directory

[jonabc]

closes #309

Two part fix to this change

1. Better handle a missing source path in an app so that it doesn't crash the overall execution of licensed.
   • This will now log an error like No such directory <path>
2. Better handling of path expansion
   • If the path specifies a directory that exists, don't expand
   • If the path expands into 0 paths, return the original configuration (which will be better handled with the first fix ☝️ )
   • For 1 or more expanded paths, use the existing value mapping that was previously used for 2 or more expanded paths.