Update translation files

Updated by "Remove blank strings" hook in Weblate.

Translation: Auxio/Strings
Translate-URL: https://hosted.weblate.org/projects/auxio/strings/

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

@@ -131,6 +131,5 @@
     <string name="lbl_soundtrack">Σάουντρακ</string>
     <string name="lbl_live_group">Ζωντανά</string>
     <string name="set_dirs">Φάκελοι μουσικής</string>
-    <string name="lbl_singles"></string>
     <string name="lbl_track">Μουσικο κομματι</string>
 </resources>