providers: Removed unused import

src/main/java/com/owncloud/android/providers/DocumentsStorageProvider.java

@@ -61,7 +61,6 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Vector;
 
 @TargetApi(Build.VERSION_CODES.KITKAT)
 public class DocumentsStorageProvider extends DocumentsProvider {