JIRA DVCS plugin can't be upgraded from version 1.3.1.1 to 1.4.0.1 if JIRA is not using the default SQL Server schema (dbo)

If JIRA is connected to SQL Server database using other than the default schema (dbo), then the JIRA DVCS plugin can't be upgraded from the version 1.3.1.1 to 1.4.0.1.

Steps to reproduce the problem:

1. Deploy JIRA 5 or 6, and connect it to SQL Server database using a custom schema (eg: jiraschema)
2. Install JIRA DVCS plugin version 1.3.1.1
3. Integrate JIRA with Bitbucket or Git account
4. Upgrade the plugin via UPM, and the following error will appear after upgrade task:

   2013-08-05 15:18:15,650 http-bio-8082-exec-17 ERROR admin 918x747x1 oehna3 0:0:0:0:0:0:0:1 /secure/admin/ConfigureDvcsOrganizations!default.jspa [com.atlassian.velocity.DefaultVelocityManager] MethodInvocationException occurred getting message body from Velocity: java.lang.RuntimeException: java.sql.SQLException: Invalid object name 'AO_E8B6CC_CHANGESET_MAPPING'.
   java.lang.RuntimeException: java.sql.SQLException: Invalid object name 'AO_E8B6CC_CHANGESET_MAPPING'.
   	at com.atlassian.jira.plugins.dvcs.activeobjects.v3.To_12_SplitUpChangesetsMigrator.upgrade(To_12_SplitUpChangesetsMigrator.java:354)
   	at com.atlassian.activeobjects.internal.ActiveObjectUpgradeManagerImpl$1.doInTransaction(ActiveObjectUpgradeManagerImpl.java:81)
   	at com.atlassian.activeobjects.internal.ActiveObjectUpgradeManagerImpl$1.doInTransaction(ActiveObjectUpgradeManagerImpl.java:76)
   	at com.atlassian.sal.core.transaction.HostContextTransactionTemplate$1.doInTransaction(HostContextTransactionTemplate.java:25)
   	at com.atlassian.jira.DefaultHostContextAccessor.doInTransaction(DefaultHostContextAccessor.java:34)  <+2> (DelegatingMethodAccessorImpl.java:25)
   	at java.lang.reflect.Method.invoke(Method.java:597)
   [.....]
   Caused by: java.sql.SQLException: Invalid object name 'AO_E8B6CC_CHANGESET_MAPPING'.
   	at net.sourceforge.jtds.jdbc.SQLDiagnostic.addDiagnostic(SQLDiagnostic.java:368)
   	at net.sourceforge.jtds.jdbc.TdsCore.tdsErrorToken(TdsCore.java:2820)
   	at net.sourceforge.jtds.jdbc.TdsCore.nextToken(TdsCore.java:2258)
   	at net.sourceforge.jtds.jdbc.TdsCore.getMoreResults(TdsCore.java:632)
   	at net.sourceforge.jtds.jdbc.JtdsStatement.processResults(JtdsStatement.java:584)
   	at net.sourceforge.jtds.jdbc.JtdsStatement.executeImpl(JtdsStatement.java:723)
   

The problem is not reproducible when JIRA is using the default SQL Server database schema.