Fix Russian translation

A placeable was missing because Pontoon doesn't support translating
XLIFF strings with placeables and this broke the build. This CL fixes
the issue by readding the placeable to the translated string.

Change-Id: Idd3832ac90b5cdf3c29501e2b44c7d6a3f722817
diff --git a/src/lit-locales/source/ru.xlf b/src/lit-locales/source/ru.xlf
index 9a30aa5..85cf100 100644
--- a/src/lit-locales/source/ru.xlf
+++ b/src/lit-locales/source/ru.xlf
@@ -19,7 +19,7 @@
       </trans-unit>
       <trans-unit id="s6b0ed0c74667d28c" xml:space="preserve">
   <source><x id="0" equiv-text="${authorName}"/> said:</source>
-        <target>сказал:</target>
+        <target><x id="0" equiv-text="${authorName}"/> сказал:</target>
       </trans-unit>
       <trans-unit id="s98a0ccd6f423421f" xml:space="preserve">
   <source>Nested view</source>