Fixes issue 1197 for s3 module, where the file gets downloaded even if checksums match

lib/ansible/modules/cloud/amazon/s3.py

@@ -328,6 +328,12 @@ def main():
     s3_url = module.params.get('s3_url')
     src = module.params.get('src')
 
+    if overwrite not in  ['always', 'never', 'different']: 
+        if module.boolean(overwrite): 
+            overwrite = 'always' 
+        else: 
+            overwrite='never'
+
     if overwrite not in  ['always', 'never', 'different']: 
         if module.boolean(overwrite): 
             overwrite = 'always'