Fix file downloader Linux path

It wasn't using the full path for the file downloader

Author: Timse93

bantam/Forms/BantamMain.cs

@@ -1629,7 +1629,7 @@ private async void downloadToolStripMenuItem_Click(object sender, EventArgs e)
             }
 
             string shellUrl = SelectedShellUrl;
-            string fileName = fileBrowserGetFileName();
+            string fileName = fileBrowserGetFileNameAndPath();
             bool encryptResponse = Shells[shellUrl].ResponseEncryption;
             int ResponseEncryptionMode = Shells[shellUrl].ResponseEncryptionMode;