Update rewriteframes.ts

[xiaoxiaojx]

Delete useless condition judgment

[xiaoxiaojx]

private readonly _iteratee: StackFrameIteratee = (frame: StackFrame) => {
    // here ~
    if (!frame.filename) {
      return frame;
    }
    // Check if the frame filename begins with `/` or a Windows-style prefix such as `C:\`
    const isWindowsFrame = /^[A-Z]:\\/.test(frame.filename);
    const startsWithSlash = /^\//.test(frame.filename);
    if (frame.filename && (isWindowsFrame || startsWithSlash)) {

[kamilogorek]

Thanks!