python bindings: fix a typo in the sample
python bindings: fix a typo in the sample

A typo was introduced by 6be17d8e2906ed60f2f1b13a396b0b6b4c479f1b which caused
the script to crash.

The only available information during the crash was:

    terminate called after throwing an instance of 'Swig::DirectorMethodException'

What actually happened was that an undefined name ('mgg' instead of 'msg') was
used.

Signed-off-by: David Wagner <60228a510f9a76940848fa2d29321fc4edfc2119@intel.com>

mgaio/parameter-framework,dawagner/parameter-framework,clero/parameter-framework,dawagner/parameter-framework,01org/parameter-framework,mgaio/parameter-framework,krocard/parameter-framework,krocard/parameter-framework,01org/parameter-framework,miguelgaio/parameter-framework,clero/parameter-framework,mgaio/parameter-framework,dawagner/parameter-framework,krocard/parameter-framework,clero/parameter-framework,01org/parameter-framework,miguelgaio/parameter-framework,miguelgaio/parameter-framework