Rename identity mgstaking to MrsEGLD

[BubuMVX]

Hi,

Here's the signature for this commit:

{
  "message": "62366136323433326138343466643533633964383762373464353337346239313230346561633833",
  "signature": "260fd7e7fe3da187d8739cb2dbd8156b28d8bd577cfe56c2e0369ee8a9639a49757d9d422ac392fce0523cede7d811b4c03cdac00c9a00656009e5c6f71bc407",
  "address": "erd1cv0mhyrvjnkt2mrq4u8wm0087kvhwtcyp0sey4l3vf3xuylyqdfqgwn0px",
  "version": 1,
  "signer": "sdk-js"
}

Thanks !