message: Fix check for initial directory for Linux sessions
  issue
diff: @@ -66,7 +66,7 @@ class UnixBackend implements SessionBackend {
  let cwd: string = null;
  if (sessionConfig.initialDirectory != null && sessionConfig.initialDirectory !== "") {
  - const dirError = this._validateDirectoryPath(cwd);
  + const dirError = this._validateDirectoryPath(sessionConfig.initialDirectory);
  if (dirError != null) {
  preMessage += `\x0a\x0d\x0a\x0d*** Initial directory '${cwd}' couldn't be found. ***\x0a\x0d\x0a\x0d\x0a\x0d`;
  } else {
  