[PATCH] Fix typo in Storage#constructor

[Piper McCorkle]

Found this typo from TypeScript language server diagnostics.
---
 common/Storage.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/common/Storage.js b/common/Storage.js
index 398dbb4..631d6e0 100644
--- a/common/Storage.js
+++ b/common/Storage.js
@@ -61,7 +61,7 @@ class ListStore {
     this.storage = storage;
     this.items = new Set();
     browser.storage.onChanged.addListener(changes => {
-      if (!this.saving && this.key in changes) {
+      if (!this._saving && this.key in changes) {
         this.load(changes[this.key].newValue);
       }
     });
-- 
2.43.0