correct typo of depricated to deprecated

https://bugzilla.redhat.com/show_bug.cgi?id=1079295 Add mms-agent to gear with
old settings.py, check the warning message, typo in it.

The settings.py was depricated, please check your 10gen-mms-agent cartridge
documentation at 
http://openshift.github.io/documentation/oo_cartridge_guide.html#10gen-mms-agent