Changed broken link to store page

Author: marqdevx

library.properties

@@ -5,5 +5,5 @@ maintainer=Arduino <[email protected]>
 sentence=Arduino 9 Axes Motion Shield Library
 paragraph=Allows controlling each motion sensor of the 9 Axes Motion Shield.
 category=Device Control
-url=http://www.arduino.org/learning/reference/9-Axes-Motion
+url=https://store.arduino.cc/arduino-9-axis-motion-shield
 architectures=*