Update README.md

Author: fpistm

README.md

@@ -6,7 +6,7 @@
 
 
 [![GitHub release](https://img.shields.io/github/release/stm32duino/Arduino_Core_STM32.svg)](https://github.com/stm32duino/Arduino_Core_STM32/releases/latest)
-[!GitHub All Releases](https://img.shields.io/github/downloads/stm32duino/Arduino_Core_STM32/total.svg?label=downloads%20since%201.4.0)
+![GitHub All Releases](https://img.shields.io/github/downloads/stm32duino/Arduino_Core_STM32/total.svg?label=downloads%20since%201.4.0)
 [![GitHub commits](https://img.shields.io/github/commits-since/stm32duino/Arduino_Core_STM32/2.1.0.svg)](https://github.com/stm32duino/Arduino_Core_STM32/compare/2.1.0...master)