conversationmodel: no file transfer with banned contacts

Currently it is not allowed by the lrc to place video calls, audio
calls or send messages to banned contacts, but files can still be
sent. In order to be consistent with previous changes, this patch
forbids file transfer with banned contacts.

Change-Id: I99b7de9a113df3a4925707ba64a5b904626a5662
Reviewed-by: Andreas Traczyk <andreas.traczyk@savoirfairelinux.com>

src/conversationmodel.cpp

@@ -1725,6 +1725,12 @@ ConversationModel::sendFile(const std::string& convUid,
     // Retrieve final peer uri after creation of the conversation
     const auto& newPeerUri = isTemporary ? pimpl_->conversations.at(contactIndex).participants.front() : peerUri;
 
+    auto contactInfo = owner.contactModel->getContact(newPeerUri);
+    if (contactInfo.isBanned) {
+        qDebug() << "ContactModel::sendFile: denied, contact is banned";
+        return;
+    }
+
     pimpl_->lrc.getDataTransferModel().sendFile(owner.id.c_str(),
                                                 newPeerUri.c_str(),
                                                 path.c_str(),