pgsql: Fix typo in GetRunningTransactionData()

Fix typo in GetRunningTransactionData() e85662df44 made GetRunningTransactionData() calculate the oldest running transaction id within the current database. However, because of the typo, the new code uses oldestRunningXid instead of oldestDatabaseRunningXid in comparison before updating oldestDat

pgsql: Fix typo in GetRunningTransactionData()

Fix typo in GetRunningTransactionData() e85662df44 made GetRunningTransactionData() calculate the oldest running transaction id within the current database. However, because of the typo, the new code uses oldestRunningXid instead of oldestDatabaseRunningXid in comparison before updating oldestDat