Display error when current user is not allowed to reshare file/folder.

Signed-off-by: Camila San <hello@camila.codes>

src/gui/sharedialog.cpp

@@ -271,6 +271,7 @@ void ShareDialog::showSharingUi()
         auto label = new QLabel(this);
         label->setText(tr("The file can not be shared because it was shared without sharing permission."));
         label->setWordWrap(true);
+        _ui->verticalLayout->insertWidget(1, label);
         return;
     }