Support remoting adapters with no ctx.req object

Fix `Model.createOptionsFromRemotingContext()` to correctly handle
the case where `ctx.req` is not defined, e.g. when using
websocket-based adapters.

lib/model.js

@@ -1046,7 +1046,7 @@ module.exports = function(registry) {
    */
   Model.createOptionsFromRemotingContext = function(ctx) {
     return {
-      accessToken: ctx.req.accessToken,
+      accessToken: ctx.req ? ctx.req.accessToken : null,
     };
   };
 

test/model.test.js

@@ -964,6 +964,12 @@ describe.onServer('Remote Methods', function() {
         });
     });
 
+    it('sets empty options.accessToken for requests coming from websocket/primus adapters', function() {
+      const primusContext = {};
+      const opts = TestModel.createOptionsFromRemotingContext(primusContext);
+      expect(opts).to.have.property('accessToken', null);
+    });
+
     it('allows apps to add options before remoting hooks', function(done) {
       TestModel.createOptionsFromRemotingContext = function(ctx) {
         return {hooks: []};