Update ProQuest.js

See https://forums.zotero.org/discussion/40821/zotero-not-recognizing-books-chapters-dissertations-in-proquest-psycinfo/

(Maybe we should wait for more examples of different types.)
The old code was doing the following (as far as I understood it):
 * if one of the `item[i]`'s is equal to `"Government & Official Publications"` it sets `govdoc = true;`
 * if one of the `item[i]`'s contains `report` or `statute` it sets `govdocType` accordingly, which will only be returned if previously another `item[i]` set `govdoc` to true.

The new code will now simply do:
 * if one of the `item[i]`'s contains `report` or `statute` then return this.

This is not exactly the same, but I don't know if such strange cases occur (in reality) e.g. `item = [ 'report', 'book', 'government & official publication' ]` and whether order is really important here