Update rollingshutter.py

Add Yuneec H520 / E90 camera with 44ms rolling shutter speed

opendm/rollingshutter.py

@@ -19,6 +19,8 @@ RS_DATABASE = {
 
     'dji fc350': 30, # Inspire 1
     
+    'yuneec e90': 44, # Yuneec E90
+
     'gopro hero4 black': 30, # GoPro Hero 4 Black
     'gopro hero8 black': 17, # GoPro Hero 8 Black