aioble/security: Only schedule save when needed.

Was getting occasional: RuntimeError: schedule queue full

Author: pi-anl

micropython/bluetooth/aioble/aioble/security.py

@@ -57,10 +57,6 @@ def _save_secrets(arg=None):
 
     _path = _path or _DEFAULT_PATH
 
-    if not _modified:
-        # Only save if the secrets changed.
-        return
-
     with open(_path, "w") as f:
         # Convert bytes to hex strings (otherwise JSON will treat them like
         # strings).
@@ -106,8 +102,9 @@ def _security_irq(event, data):
             _secrets[key] = value
 
         # Queue up a save (don't synchronously write to flash).
-        _modified = True
-        schedule(_save_secrets, None)
+        if not _modified:
+            _modified = True
+            schedule(_save_secrets, None)
 
         return True