Blender Git Loki

Fix T87401: Drop-down can apply the wrong modifier

The trouble was that there was a context pointer "modifier" in the
property editor context that returned the active modifier. But the
"modifier" variable was already used in many places, for pointers
that are *not* equivalent to the active modifier.

The context pointer for the active modifier was unecessary anyway.
If we need to access a context pointer for the active modifier in the
property editor then we can add it. Until then it only adds confusion.