How to find 'active' snapshots that cause

I’m getting the same error as Julien Lancelot answered re:

Failed to upgrade SonarQube from 4.5 to 5.0.1

2015.02.18 14:56:26 INFO  web[DbMigration]  ==  PopulateProjectsUuidColumns: migrating ====================================
2015.02.18 14:56:43 ERROR web[o.s.s.d.m.DatabaseMigrator]  Fail to execute database migration: org.sonar.server.db.migrations.v50.PopulateProjectsUuidColum
nsMigration
org.apache.ibatis.exceptions.PersistenceException:
### Error querying database.  Cause: java.lang.NullPointerException
### Cause: java.lang.NullPointerException
        at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26) ~[mybatis-3.2.7.jar:3.2.7]
        at org.apache.ibatis.session.defaults.DefaultSqlSession.select(DefaultSqlSession.java:130) ~[mybatis-3.2.7.jar:3.2.7]
        at org.apache.ibatis.session.defaults.DefaultSqlSession.select(DefaultSqlSession.java:122) ~[mybatis-3.2.7.jar:3.2.7]
        at org.sonar.core.persistence.DbSession.select(DbSession.java:125) ~[sonar-core-5.0.jar:na]
        at org.sonar.server.db.migrations.v50.PopulateProjectsUuidColumnsMigration.execute(PopulateProjectsUuidColumnsMigration.java:65) ~[sonar-server-5.0.jar:na]

Julian mentioned

With the help of the SQL query and the modified jar to add some debug, I've finally found from where the issue is coming : your project with id 39554 have 2 active snapshots (1234385 and 1234386). This use case is not managed as this should never happen.

How can I identify the mentioned ‘active’ snapshots and delete them so this step succeeds?

Answered by Julian via email, here is the sql

SELECT snapshots.id, COUNT() FROM projects INNER JOIN snapshots ON snapshots.project_id=projects.id AND snapshots.islast=true GROUP BY snapshots.id HAVING COUNT() > 1