Scry doesn't handle missing plugin descriptions correctly

[ardagnir]

It looks like vizardry handles plugins incorrectly in Scry if there missing descriptions.

Testcase: Scry markdown

[dbeniamine]

Fixed by commit 1ffee76

The problem was that empty values in github search results looks likes:

"description": null,

While a normal answer looks like:

"description": "hello world",

Therefore replacing every null, by "", in the search result before creating list of plugins and description fix the issue.