Drop log level for incorrect logging contexts to WARN if the context is wrong...

Drop log level for incorrect logging contexts to WARN if the context is wrong and DEBUG if the context is missing

synapse/util/logcontext.py

@@ -55,11 +55,14 @@ class LoggingContext(object):
             None to avoid suppressing any exeptions that were thrown.
         """
         if self.thread_local.current_context is not self:
-            logger.error(
-                "Current logging context %s is not the expected context %s",
-                self.thread_local.current_context,
-                self
-            )
+            if self.thread_local.current_context is self.sentinel:
+                logger.debug("Expected logging context %s has been lost", self)
+            else:
+                logger.warn(
+                    "Current logging context %s is not expected context %s",
+                    self.thread_local.current_context,
+                    self
+                )
         self.thread_local.current_context = self.parent_context
         self.parent_context = None