Support specials when using absolute order

[emilio-eam]

Trying to parse Animes with Kodi 19.4 as explained in the Kodi Wiki I found that, when enabling the "absolute order", if I put the Specials in the same folder or in a subfolder they are not correctly detected (unless I add additional configuration for each subfolder or parse them manually). I've seen this happen on some Animes (such as Dragon Ball).
I've tested a quick fix in the script so that it will only set the season to "1" if it was already equal or higher than one, but it will keep it as it was otherwise (so specials keep their original season and episode number). Tested it with some Animes, both with and without specials, the only one that did not work properly was not showing any episodes in absolute sort in tvdb.com (so the problem did not seem to be in the algorithm, but in the information source).
You can check it in the PR #54.