Suppress warnings about "dtype size changed" when loading numpy-dependent libs

[achimnol]

ref) https://stackoverflow.com/questions/40845304/runtimewarning-numpy-dtype-size-changed-may-indicate-binary-incompatibility

Let's suppress this warning until we have real problems with it.

• Kernel runner's Python inproc.py for query mode execution
• sitecustomize.py for Python batch mode execution