[Spanish l10n] Fixed duplicated string

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

@@ -48,7 +48,6 @@
     <string name="recommended">(Recomendado)</string>
     <string name="search">Motor de búsqueda</string>
     <string name="search_hint">Buscar</string>
-    <string name="custom_url">URL personalizada</string>
     <string name="wideViewPort">Utilizar viewport normal</string>
     <string name="overViewMode">Visualizar la página de lejos al cargar</string>
     <string name="restore">Restaurar pestañas cerradas al iniciar</string>