Trying to set metadata results in error (Python 3)

[alexanderaltanis]

When trying to set metadata for a set of files I want to upload, I get the following error:

[Exception] 'dict' object has no attribute 'iteritems'
Exception in thread Thread-1:ad(s)]
Traceback (most recent call last):
  File "/home/username/.local/bin/s4cmd.py", line 520, in run
    self.__class__.__dict__[func_name](self, *args, **kargs)
  File "/home/username/.local/bin/s4cmd.py", line 129, in wrapper
    ret = func(*args, **kargs)
  File "/home/username/.local/bin/s4cmd.py", line 1332, in upload
    self.s3.put_object(Bucket=s3url.bucket,
  File "/home/username/.local/bin/s4cmd.py", line 399, in wrapped_method
    merged_kargs = self.merge_opt_params(method, kargs)
  File "/home/username/.local/bin/s4cmd.py", line 432, in merge_opt_params
    for k, v in getattr(self.opt, key).iteritems():
AttributeError: 'dict' object has no attribute 'iteritems'
[...]

.iteritems has been removed from dict in Python 3.

I tried just changing it locally to .items and that worked, but I'd rather let you fix it :)