Found myself affected by this bug too. I made a quick fix that you can apply by modifying /usr/share/shutter/resources/system/upload_plugins/upload/Imgur.pm file. You can find patch file attached.
Found myself affected by this bug too. I made a quick fix that you can apply by modifying /usr/share/ shutter/ resources/ system/ upload_ plugins/ upload/ Imgur.pm file. You can find patch file attached.