Fix exception when handling empty signature parameters. (#137)
Fix exception when handling empty signature parameters. (#137)

* Fix exception when handling empty signature parameters.

Prior to this commit an exception is raised if the function signature
returned by a language server does neither contain a `parameters` nor
`params` field.

The error message was:

   LSP: active signature {'label': 'active_window()', 'documentation': ''}
   LSP: params None
   LSP: error handling response 10
   LSP: Error handling server content: 'NoneType' object is not iterable

This commit fixes this issue by a fallback to an empty dictionary.

* Don't fall back to object, remove old pyls workaround

tomv564/LSP