Revert "PLT-1800 Load server side locale from the config.json (#3076)"

This reverts commit 34beaa569b.

webapp/components/admin_console/admin_sidebar.jsx

@@ -292,15 +292,6 @@ export default class AdminSidebar extends React.Component {
                                         />
                                     }
                                 />
-                                <AdminSidebarSection
-                                    name='localization'
-                                    title={
-                                        <FormattedMessage
-                                            id='admin.sidebar.localization'
-                                            defaultMessage='Localization'
-                                        />
-                                    }
-                                />
                                 <AdminSidebarSection
                                     name='users_and_teams'
                                     title={