chore: remove rogue j (#2718)

i did not expect a j there.

Author: olizilla

README.md

@@ -1270,7 +1270,7 @@ http://localhost:5002/debug/metrics/prometheus
 
 ![](/img/architecture.png)
 
-[Annotated version](https://user-images.githubusercontent.com/1211152/47606420-b6265780-da13-11e8-923b-b365a8534e0e.png)j
+[Annotated version](https://user-images.githubusercontent.com/1211152/47606420-b6265780-da13-11e8-923b-b365a8534e0e.png)
 
 What does this image explain?