fix wrong property name in install documentation
fix wrong property name in install documentation

This pull request corrects a copy and error that would have prevented
an OSIAM installation from starting correctly.

tkrille/osiam-osiam,tkrille/osiam-osiam,fwilhe/osiam,fwilhe/osiam,osiam/osiam,tkrille/osiam-osiam,osiam/osiam,fwilhe/osiam,osiam/osiam