/:db requests crash on unauthorized access

[QuentinRoy]

Requests seem to crash when trying to access unauthorized database with the following (not explanatory) error message:

(node:10101) UnhandledPromiseRejectionWarning: TypeError: Cannot set property 'instance_start_time' of undefined
    at /Users/qroy/Workspace/Code/personality-adaptation/node_modules/express-pouchdb/lib/routes/db.js:100:32
    at /Users/qroy/Workspace/Code/personality-adaptation/node_modules/promise-nodify/index.js:22:7
    at <anonymous>

After fiddling for a few hours with the code, I believe the error is due to pouchdb-size swallowing errors coming from previous handlers here:

pouchdb-server/packages/node_modules/pouchdb-size/lib/index.js

Lines 38 to 42 in 89d59b0

	}).catch(function () {
	//surpress - .info() should keep functioning if for some reason
	//it's impossible to get the disk_size.
	return resp;
	});

The catch is supposed to suppress exceptions when the db size can't be get, but actually swallow any exceptions thrown by orig. In particular, it swallows this one:

pouchdb-server/packages/node_modules/pouchdb-security/lib/index.js

Lines 62 to 64 in 89d59b0

	if (!checkAllowed(userCtx, security)) {
	throw401();
	}

When this happens resp (in pouchdb-size's catch block), isn't set yet, and the promise is resolved with undefined, resulting in the unexpected error above:

pouchdb-server/packages/node_modules/express-pouchdb/lib/routes/db.js

Line 100 in 89d59b0

info.instance_start_time = startTime.toString();