Fix Issue14721: Send Content-length: 0 for empty body () in the http.client requests
diff --git a/Lib/http/client.py b/Lib/http/client.py
index d226f63..97a7155 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -997,7 +997,7 @@
 
         self.putrequest(method, url, **skips)
 
-        if body and ('content-length' not in header_names):
+        if body is not None and ('content-length' not in header_names):
             self._set_content_length(body)
         for hdr, value in headers.items():
             self.putheader(hdr, value)