Only remove duplicated statistics on error

[emontnemery]

Proposed change

Only remove duplicated statistics on error

We first try to recreate the statistics indices, which will fail if there are duplicates.
If creating the index fails, remove duplicates then try again

This is done to speed up the migration step

Type of change

• Dependency upgrade
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• This PR fixes or closes issue: fixes #
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[probot-home-assistant]

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[pvizeli]

Suggested change

	try:
	_create_index(connection, "statistics", "ix_statistics_statistic_id_start")
	_create_index(
	connection,
	"statistics_short_term",
	"ix_statistics_short_term_statistic_id_start",
	)
	except DatabaseError:
	# There may be duplicated statistics entries, delete duplicated statistics
	# and try again
	delete_duplicates(instance, session)
	_create_index(connection, "statistics", "ix_statistics_statistic_id_start")
	_create_index(
	connection,
	"statistics_short_term",
	"ix_statistics_short_term_statistic_id_start",
	)
	for _ in range(2):
	try:
	_create_index(connection, "statistics", "ix_statistics_statistic_id_start")
	_create_index(
	connection,
	"statistics_short_term",
	"ix_statistics_short_term_statistic_id_start",
	)
	except DatabaseError:
	# There may be duplicated statistics entries, delete duplicated statistics
	# and try again
	delete_duplicates(instance, session)
	else:
	break

[pvizeli]

with that loop, he need less doublicate code

[emontnemery]

It's pretty nice.
Maybe we should only call delete_duplicates the first iteration though?

hmm