Update translation files

Updated by "Remove blank strings" hook in Weblate.

Translation: EasyWatermark/App Strings
Translate-URL: https://hosted.weblate.org/projects/easywatermark/app-strings/

app/src/main/res/values-ru/strings.xml

@@ -6,5 +6,4 @@
     <string name="about_title_version">Версия</string>
     <string name="back">Назад</string>
     <string name="dialog_save_config_quality">Качество</string>
-    <string name="dialog_cancel_exist_confirm"></string>
 </resources>