FtsManager.reindexNextBatch method doesn't work

[Ilya-c]

Environment

• Platform version: 7.2.8

Description of the bug or enhancement

Can be reproduced in the JMX console

• Enable fts (set Enabled flag in the variables table to true)
• Execute asyncReindexAll() method
• Execute reindexNextBatch() method

This will cause exception:

java.lang.IllegalStateException: No active transaction
    at com.haulmont.cuba.core.sys.PersistenceImpl.getEntityManager(PersistenceImpl.java:170)
    at com.haulmont.cuba.core.sys.PersistenceImpl.getEntityManager(PersistenceImpl.java:164)
    at com.haulmont.fts.core.sys.EntitiesCollector.loadResults(EntitiesCollector.java:110)
    at com.haulmont.fts.core.app.FtsManager.executeInStoreTx(FtsManager.java:558)
    at com.haulmont.fts.core.app.FtsManager.reindexNextBatch(FtsManager.java:447)