INE-SPAIN: fix missing TSV file error

Related to this discussion

Context:

• Open https://api.next.nomics.world/series?series_ids=INE-SPAIN%2F9130%2Fa.00.051.0.index&format=json

Problem:

• TSV file is not found (error is "Could not find TSV file corresponding to series ('INE-SPAIN', '9130', 'a.00.051.0.index')")

Investigation by @cbenz:

• I checked that series a.00.051.0.index is mentioned in dataset.json of 9130 but a.00.051.0.index.tsv is not found in dataset directory (9130).
• But a.00.051.0.index.tsv is also mentioned in dataset.json of 27068, and exists in dataset directory (27068)

Expected:

• The TSV should be found OR the series is not mentioned in dataset.json, for dataset 9130.