Avoid performing redundant release

Author: kibertoad

src/Lock.ts

@@ -134,7 +134,9 @@ export abstract class Lock {
  if (this._refreshTimeInterval > 0) {
  this._stopRefresh()
  }
- await this._release()
+ if (this._acquired) {
+ await this._release()
+ }
  this._acquired = false
  }
 }