Fix gen1 single chain for gen2 tradeback scenario

invalid mon -> make sure array is big enough for later move parsing

https://projectpokemon.org/home/forums/topic/47283-unhandled-exception-when-importing-set-from-clipboard-after-opening-gen-i-save-file/

PKHeX.Core/Legality/Evolutions/EvolutionChain.cs

@@ -29,7 +29,7 @@ private static List<EvoCriteria>[] GetChainBase(int maxgen)
 
         private static List<EvoCriteria>[] GetChainSingle(PKM pkm, List<EvoCriteria> CompleteEvoChain)
         {
-            var chain = GetChainBase(pkm.Format);
+            var chain = GetChainBase(Math.Max(2, pkm.Format));
             chain[pkm.Format] = CompleteEvoChain;
             return chain;
         }