Russian localization (search box)

Russian localization of recently added messages appearing in the search interface. Also, fix for the missing sync timestamp bug (caused by my earlier commit 'Complete Russian localization' 8f0b353341dfbf306310da002355a351c19e52cd).

src/_locales/ru/messages.yml

@@ -282,7 +282,7 @@ labelSync:
   message: Синхронизация с облачным  хранилищем
 lastSync:
   description: Label for last sync timestamp.
-  message: 'Последняя синхронизация: '
+  message: Последняя синхронизация в $1.
 msgSyncInit:
   description: Message shown when sync service is initializing.
   message: Установление соединения...
@@ -406,10 +406,10 @@ labelNotifyUpdates:
   message: Уведомлять об обновлениях скриптов.
 installFrom:
   description: Label for button to install script from a userscript site.
-  message: ''
+  message: Установить с $1
 labelSearchScript:
   description: Placeholder for script search box.
-  message: ''
+  message: Посик скриптов...
 labelNoSearchScripts:
   description: Message shown when no script is found in search results.
-  message: ''
+  message: Скрипты не найдены.