User accounts can include blanks when used with LDAP

Current Situation

Since JOC-254 LDAP user accounts with spaces in their names can not authenticate and the following error is raised:

Exception while logging in John%20Doe LDAP naming error while attempting to authenticate user.: Could not login with user: John Doe password:*******

Desired Behavior

The authentication for LDAP user accounts with spaces in their names should be possible.
To assign a role to this LDAP user account you can use a mapping from LDAP groups to roles which are specified in the [roles] section of the shiro.ini.
It is also possible to specify the role without LDAP group mapping, in which the user account is assigned the role in the [users] section of the shiro.ini.
In this case the user account must include %20 instead of a blank. For example

[users]
John%20Doe=,all

When not using LDAP then blanks in user accounts are not allowed.