[App] notification issue crash on server side with yuukan streamy

[danlg]

Exception in callback of async function: TypeError: Cannot read property 'userId' of null
2153     at packages/yuukan_streamy/packages/yuukan_streamy.js:338:1
2154     at packages/underscore/underscore.js:200:1
2155     at _.each._.forEach (packages/underscore/underscore.js:113:1)
2156     at Function._.filter._.select (packages/underscore/underscore.js:199:1)
2157     at Object.Streamy.socketsForUsers (packages/yuukan_streamy/packages/yuukan_streamy.js:337:1)
2158     at packages/smartix_lib/server/methods.js:152:1
2159     at Array.map (/opt/carmel/app.1.2.2.b350/programs/server/npm/node_modules/meteor/es5-shim/node_modules/es5-shim/es5-shim.js:466:33)
2160     at [object Object].Meteor.methods.doPushNotification (packages/smartix_lib/server/methods.js:150:1)
2161     at maybeAuditArgumentChecks (packages/ddp-server/livedata_server.js:1704:12)
2162     at packages/ddp-server/livedata_server.js:1617:18

See also #225

[danlg]

Also distinguish better real user not found and users who chose not to be notified.

mdoPushNotification, cannot notify, user not found  mMRyymyad7LDY8Lad
2131 ^[[33m[2016-09-20 18:40:25.307] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  tWJ9MWDScRRGzgzWx
2132 ^[[33m[2016-09-20 18:40:25.745] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  kgEYSpYhnQkWzFkFa
2133 ^[[33m[2016-09-20 18:40:28.327] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  S7uBG43msSuWGdGfA
2134 ^[[33m[2016-09-20 18:41:01.276] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  kgEYSpYhnQkWzFkFa
2135 ^[[33m[2016-09-20 18:41:01.504] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  tWJ9MWDScRRGzgzWx
2136 ^[[33m[2016-09-20 18:41:01.517] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  mMRyymyad7LDY8Lad
2137 ^[[33m[2016-09-20 18:41:03.218] [WARN] lg - ^[[39mdoPushNotification, cannot notify, user not found  S7uBG43msSuWGdGfA