Fix BMAC button

Author: frankie567

README.md

@@ -13,7 +13,7 @@
 [![PyPI version](https://badge.fury.io/py/fastapi-users-db-mongodb.svg)](https://badge.fury.io/py/fastapi-users-db-mongodb)
 [![Downloads](https://pepy.tech/badge/fastapi-users-db-mongodb)](https://pepy.tech/project/fastapi-users-db-mongodb)
 <p align="center">
-<a href="https://github.com/sponsors/frankie567"><img src="https://md-btn.deta.dev/button.svg?text=Buy%20me%20a%20coffee%20%E2%98%95%EF%B8%8F&bg=ef4444&w=200&px=40"></a>
+<a href="https://github.com/sponsors/frankie567"><img src="https://md-btn.deta.dev/button.svg?text=Buy%20me%20a%20coffee%20%E2%98%95%EF%B8%8F&bg=ef4444&w=200&h=50"></a>
 </p>
 
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