registry: avoid phantom cache signaling

registry.patch

diff --git odoo/modules/registry.py odoo/modules/registry.py
index 907e13ef4ae5..c3c317b77f0d 100644
--- odoo/modules/registry.py
+++ odoo/modules/registry.py
@@ -616,7 +616,6 @@ class Registry(Mapping):
                 if self.cache_sequence != c:
                     _logger.info("Invalidating all model caches after database signaling.")
                     self._clear_cache()
-                    self.cache_invalidated = False
                 if self.cache_longterm_sequence != cl:
                     _logger.info("Invalidating longterm cache after database signaling.")
                     self._clear_cache_longterm()
@@ -625,6 +624,10 @@ class Registry(Mapping):
             self.cache_sequence = c
             self.cache_longterm_sequence = cl
 
+            # prevent re-signaling the reactive clear_cache() above, or any residual one that
+            # would be inherited from the master process (for the first request in pre-fork mode)
+            self.cache_invalidated = False
+
         return self
 
     def signal_changes(self):