Remove redundant condition from equals snippet

snippets/equals.md

@@ -14,7 +14,6 @@ const equals = (a, b) => {
   if (a === b) return true;
   if (a instanceof Date && b instanceof Date) return a.getTime() === b.getTime();
   if (!a || !b || (typeof a !== 'object' && typeof b !== 'object')) return a === b;
-  if (a === null || a === undefined || b === null || b === undefined) return false;
   if (a.prototype !== b.prototype) return false;
   let keys = Object.keys(a);
   if (keys.length !== Object.keys(b).length) return false;