Fix indentation.

Change-Id: I7f19b35032a686dfb2f776e8ff3527366b008331
Reviewed-on: https://code.wireshark.org/review/25718
Reviewed-by: Guy Harris <guy@alum.mit.edu>

ui/qt/capture_file_dialog.cpp

@@ -740,7 +740,7 @@ void CaptureFileDialog::preview(const QString & path)
 
     if(status == PREVIEW_READ_ERROR) {
         // XXX - give error details?
-    	g_free(err_info);
+        g_free(err_info);
         preview_size_.setText(tr("%1, error after %Ln packet(s)", "", packets)
                               .arg(size_str));
         return;