delete local keys on account removal

src/main/java/com/owncloud/android/jobs/AccountRemovalJob.java

@@ -40,6 +40,7 @@ import com.owncloud.android.datamodel.SyncedFolderProvider;
 import com.owncloud.android.datamodel.UploadsStorageManager;
 import com.owncloud.android.ui.activity.ContactsPreferenceActivity;
 import com.owncloud.android.ui.events.AccountRemovedEvent;
+import com.owncloud.android.utils.EncryptionUtils;
 import com.owncloud.android.utils.FileStorageUtils;
 import com.owncloud.android.utils.FilesSyncHelper;
 
@@ -115,6 +116,10 @@ public class AccountRemovalJob extends Job implements AccountManagerCallback<Boo
                 filesystemDataProvider.deleteAllEntriesForSyncedFolder(Long.toString(syncedFolderId));
             }
 
+            // delete stored E2E keys 
+            arbitraryDataProvider.deleteKeyForAccount(account.name, EncryptionUtils.PRIVATE_KEY);
+            arbitraryDataProvider.deleteKeyForAccount(account.name, EncryptionUtils.PUBLIC_KEY);
+
             return Result.SUCCESS;
         } else {
             return Result.FAILURE;