pae_interaction metrics don't show up in prediction_results.json when predicting from fasta input

[rdkibler]

This sequence was expected to have PAE_interaction scores:

>RK390_asu
GWSPELALQNLQSIVEAVRVSVRQAKEQGDEELLERVARQAERAARQAEKIAREARKRGNLELALKALQILVNAAYVLAEIARDRGNEELLEKAARLAEEAARQAEEIWEQLRKEGNWQLANKAERILIQAAEVLAEIAKDRGNEELLRKSIELSQRVAERSQEAAEQLQKRGE/GWSPELALQNLQSIVEAVRVSVRQAKEQGDEELLERVARQAERAARQAEKIAREARKRGNLELALKALQILVNAAYVLAEIARDRGNEELLEKAARLAEEAARQAEEIWEQLRKEGNWQLANKAERILIQAAEVLAEIAKDRGNEELLRKSIELSQRVAERSQEAAEQLQKRGE/GWSPELALQNLQSIVEAVRVSVRQAKEQGDEELLERVARQAERAARQAEKIAREARKRGNLELALKALQILVNAAYVLAEIARDRGNEELLEKAARLAEEAARQAEEIWEQLRKEGNWQLANKAERILIQAAEVLAEIAKDRGNEELLRKSIELSQRVAERSQEAAEQLQKRGE

however

{
  "mean_plddt": 83.21431732177734,
  "recycles": 5,
  "tol": 1.3919907808303833,
  "model": "1",
  "type": "monomer_ptm",
  "seed": "0",
  "mean_pae_interaction": NaN,
  "mean_pae_intra_chain_A": 5.104187965393066,
  "mean_pae_intra_chain_B": 5.184686183929443,
  "mean_pae_intra_chain_C": 5.011816501617432,
  "mean_pae_intra_chain": 5.100229740142822,
  "mean_pae": 14.246170997619629,
  "pTMscore": 0.5959139466285706,
  "elapsed_time": 192.30866289138794
}

If I had to guess, this is a bug related to the chain detection/RMSD code