Remove unnecessary imports in FileUploader

src/com/owncloud/android/files/services/FileUploader.java

@@ -52,8 +52,6 @@ import com.owncloud.android.ui.activity.FailedUploadActivity;
 import com.owncloud.android.ui.activity.FileActivity;
 import com.owncloud.android.ui.activity.FileDisplayActivity;
 import com.owncloud.android.ui.activity.InstantUploadActivity;
-import com.owncloud.android.ui.preview.PreviewImageActivity;
-import com.owncloud.android.ui.preview.PreviewImageFragment;
 import com.owncloud.android.utils.ErrorMessageAdapter;
 import com.owncloud.android.utils.Log_OC;
 import com.owncloud.android.utils.NotificationBuilderWithProgressBar;