Fix correct spellchecker locale not selected for non en-US locales

app.getLocale() should be called after app.on('init') event.
spellCheckerLocale is removed from defaultPreferences.js

src/common/config/defaultPreferences.js

@@ -15,7 +15,6 @@ const defaultPreferences = {
   },
   showUnreadBadge: true,
   useSpellChecker: true,
-  spellCheckerLocale: 'en-US',
 };
 
 module.exports = defaultPreferences;

src/common/settings.js

@@ -12,11 +12,8 @@ function merge(base, target) {
 const defaultPreferences = require('./config/defaultPreferences');
 const upgradePreferences = require('./config/upgradePreferences');
 
-function loadDefault(spellCheckerLocale) {
-  const config = JSON.parse(JSON.stringify(defaultPreferences));
-  return Object.assign({}, config, {
-    spellCheckerLocale: spellCheckerLocale || defaultPreferences.spellCheckerLocale || 'en-US',
-  });
+function loadDefault() {
+  return JSON.parse(JSON.stringify(defaultPreferences));
 }
 
 function hasBuildConfigDefaultTeams(config) {