VMM/serviceset: Fixed a conditional ProgrammingError.
Affects only setups with Dovecot < v1.2.beta2. Actually the SQL query in
method ServiceSet._load_by_services wasn't updated.
Removed unnecessary code, which would have also produced a
ProgrammingError, if it would have been correct.
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Installation
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.. toctree::
:maxdepth: 1
installation/prerequisites
installation/system_preparation
installation/postgresql_configuration
installation/dovecot_configuration
installation/postfix_configuration
installation/install_vmm