Fixes ec2.py assume_role. (#37357)

* Fixes ec2.py assume_role

Previously when connect_to_aws was called it updated the credentials in place.  "connect_to_aws" is called multiple times: on the second run it tries to assume the same role it is already using, and potentially failing depending on your iam policies.

contrib/inventory/ec2.py

@@ -159,6 +159,7 @@ import os
 import argparse
 import re
 from time import time
+from copy import deepcopy
 import boto
 from boto import ec2
 from boto import rds
@@ -569,7 +570,7 @@ class Ec2Inventory(object):
         return connect_args
 
     def connect_to_aws(self, module, region):
-        connect_args = self.credentials
+        connect_args = deepcopy(self.credentials)
 
         # only pass the profile name if it's set (as it is not supported by older boto versions)
         if self.boto_profile: