Fix destruction of synapses when destroying segment

[dan-mk]

When the predictedSegmentDecrement TM parameter is set to some value greater than 0, I was getting this error:

Using the destroySynapse function prevents the error in my tests.

[rhyolight]

@dan-mk Can you update the test suite to fail when predictedSegmentDecrement is non-zero? It would be best to expose this as an error in an existing test suite.

[rhyolight]

BTW @dan-mk, this repository is in maintenance mode. There is no guarantee this contribution will be merged anytime soon. See the README for details. The currently active HTM C++/Python project is https://github.com/htm-community/htm.core

[dan-mk]

@rhyolight I'm not sure about the right way to contribute to the test suite, so I'm attaching a modified "hello_tm" that should show the error before 60k iterations. If it does not, I've probably done something wrong

hello_tm.zip

I understand this repository is in maintenance mode and that it's not a critical bug (since it seems like I'm the first one having problems with this), so no problem if it's not merged

I'm also aware about the community repository, but I had the same error with its code, except that it gave me a segfault which is not as easy to debug haha