updated headers call in urllib3

Author: HugoMario

src/main/resources/handlebars/python/rest.mustache

@@ -34,11 +34,11 @@ class RESTResponse(io.IOBase):
 
     def getheaders(self):
         """Returns a dictionary of the response headers."""
-        return self.urllib3_response.getheaders()
+        return self.urllib3_response.headers
 
     def getheader(self, name, default=None):
         """Returns a given response header."""
-        return self.urllib3_response.getheader(name, default)
+        return self.urllib3_response.headers.get(name, default)
 
 
 class RESTClientObject(object):