Update Vamsi's gh link in maintainer doc (opensearch-project#2303)

Signed-off-by: Jialiang Liang <[email protected]>

Author: RyanL1997

MAINTAINERS.md

@@ -15,7 +15,7 @@ This document contains a list of maintainers in this repo. See [opensearch-proje
 | Lior Perry              | [YANG-DB](https://github.com/YANG-DB)           | Amazon      |
 | Simeon Widdis           | [swiddis](https://github.com/swiddis)           | Amazon      |
 | Chen Dai                | [dai-chen](https://github.com/dai-chen)         | Amazon      |
-| Vamsi Manohar           | [vamsi-amazon](https://github.com/vamsi-amazon) | Amazon      |
+| Vamsi Manohar           | [vamsi-amazon](https://github.com/vamsimanohar) | Amazon      |
 | Peng Huo                | [penghuo](https://github.com/penghuo)           | Amazon      |
 | Sean Kao                | [seankao-az](https://github.com/seankao-az)     | Amazon      |
 | Anirudha Jadhav         | [anirudha](https://github.com/anirudha)         | Amazon      |