new track fx envelope points are inserted despite automation lane not armed

- create a new track
- insert a plug-in into its track fx
- set automation mode for the track to write
- create an automation lane for one of the fx parameters
- draw an automation envelope for the parameter
- add a second automation lane for another parameter
- set the first automation lane to not armed to protect it
- draw an automation envelope for the second parameter

New envelope points will be inserted into the first ("protected") envelope. They will be inserted at all locations where playback is started.

If the track has a volume and/or pan envelope as well (set to not armed for automation), those will NOT be affected by the issue.

Discussion thread: http://forum.cockos.com/showthread.p...53#post1350553