Update parse-multipart-data to avoid sourcemap warning & assorted bugs

Sourcemap warning was actively annoying, haven't actually run into the
bugs (header order being significant, and 'name' field being missing)
but it's good to bring the fixes in regardless.

Author: pimterry

Diff for: package.json

@@ -192,7 +192,7 @@
     "lodash": "^4.16.4",
     "native-duplexpair": "^1.0.0",
     "node-forge": "^1.2.1",
-    "parse-multipart-data": "^1.3.0",
+    "parse-multipart-data": "^1.4.0",
     "performance-now": "^2.1.0",
     "portfinder": "1.0.28",
     "typed-error": "^3.0.2",