restore merge config guard

Author: zombieJ

src/hooks/useNotification.tsx

@@ -53,17 +53,15 @@ function mergeConfig<T>(...objList: Partial<T>[]): T {
   const clone = {} as T;
 
   objList.forEach((obj) => {
-    if (!obj) {
-      return;
-    }
-
-    Object.keys(obj).forEach((key) => {
-      const value = obj[key as keyof T];
+    if (obj) {
+      Object.keys(obj).forEach((key) => {
+        const value = obj[key as keyof T];
 
-      if (value !== undefined) {
-        clone[key as keyof T] = value;
-      }
-    });
+        if (value !== undefined) {
+          clone[key as keyof T] = value;
+        }
+      });
+    }
   });
 
   return clone;