Force python wrapper to be build as a shared lib

wrappers/python/CMakeLists.txt

@@ -64,7 +64,7 @@ endif()
 
 add_custom_target(liblinphone-python-wrapper ALL DEPENDS ${PYLINPHONE_DEPENDENCIES})
 
-add_library(pylinphone pylinphone.c)
+add_library(pylinphone SHARED pylinphone.c)
 add_dependencies(pylinphone liblinphone-python-wrapper)
 
 # This way user will be able to do from pylinphone import linphone