Reset the stream backoff timeout when the url updates (#66426)

Reset the stream backoff timeout when the url updates, meant to improve the retry behavior
for nest cameras. The problem is the nest url updates faster than the stream reset time
so the wait timeout never resets if there is a temporarily problem with the new url. In particular
this *may* help with the flaky cloud nest urls, but seems more correct otherwise.

homeassistant/components/stream/__init__.py

@@ -342,7 +342,9 @@ class Stream:
             stream_state.discontinuity()
             if not self.keepalive or self._thread_quit.is_set():
                 if self._fast_restart_once:
-                    # The stream source is updated, restart without any delay.
+                    # The stream source is updated, restart without any delay and reset the retry
+                    # backoff for the new url.
+                    wait_timeout = 0
                     self._fast_restart_once = False
                     self._thread_quit.clear()
                     continue