Fix remote server can not be selected on Android Viewer

Change-Id: Ic08253c3732f963eec6f97e6bd0530f95eb2916a
Reviewed-on: https://gerrit.libreoffice.org/57072
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

android/source/src/java/org/libreoffice/storage/owncloud/OwnCloudProvider.java

@@ -181,6 +181,6 @@ public class OwnCloudProvider implements IDocumentProvider,
 
     @Override
     public boolean checkProviderAvailability(Context context) {
-        return result != null && this.result.isSuccess();
+        return client != null;
     }
 }