fixup! Bug 40597: Implement TorSettings module

Bug 41114: Refactor TorConnect.

Check if the current state is already transitioning, and refusing any
additional transition request.

toolkit/modules/TorConnect.sys.mjs

@@ -876,6 +876,12 @@ export const TorConnect = {
   },
 
   async _changeState(newState, ...args) {
+    if (this._stateHandler.transitioning) {
+      // Avoid an exception to prevent it to be propagated to the original
+      // begin call.
+      lazy.logger.warn("Already transitioning");
+      return;
+    }
     const prevState = this._stateHandler;
 
     // ensure this is a valid state transition