"i==1" in mimn.py Line84 should be changed by "i>=self.read_head_num"

[FuYooou]

I think "i==1" in mimn.py Line84 should be changed by "i>=self.read_head_num".
From my point of view, this "i==1" is used to limit the operation only on write head weight when the self.read_head_num==1 and self.write_head_num==1.
But these two parameter can be changes in the code, so this "i==1" can cause problem when self.read_head_num!=1 or self.write_head_num!=1.