gm8_sprout: Edit installation guide

Change-Id: Ie668cb24da18650f04c9396f801a6d85ca1eaa24
diff --git a/_google/androidonefifthgengm8.markdown b/_google/androidonefifthgengm8.markdown
index ecf90bc..e63a664 100644
--- a/_google/androidonefifthgengm8.markdown
+++ b/_google/androidonefifthgengm8.markdown
@@ -19,7 +19,8 @@
 
 
 <div class='page-heading'>Installation:</div>
+IMPORTANT : Only works with "9.0 April sec. patch!"
+
 Install on your active slot
 
-Sample : fastboot flash boot_a twrp.img or fastboot flash boot_b twrp.img
-
+Sample : fastboot flash boot_(activeslot) twrp.img