py/strict_mode: Handle overrides of module variables specially.
py/strict_mode: Handle overrides of module variables specially.

Such overrides naturally happen while executing "import" statements, so
don't warn about them.

Change-Id: Idfc5da53dad70e86a2139ceddbd52211620c4981
Signed-off-by: Paul Sokolovsky <9dc5061f178bb11813e14f1ed02ba27eaf21fa5d@users.sourceforge.net>

pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython,pfalcon/micropython