Check Android version before actually doing anything

Close #233

scripts/addon.d.sh

@@ -39,6 +39,9 @@ main() {
 
   api_level_arch_detect
 
+  # Check if system root is installed and remove
+  remove_system_su
+
   recovery_actions
 
   find_boot_image

scripts/flash_script.sh

@@ -66,14 +66,14 @@ getvar KEEPVERITY
 getvar KEEPFORCEENCRYPT
 getvar BOOTIMAGE
 
-# Check if system root is installed and remove
-remove_system_su
-
 # Detect version and architecture
 api_level_arch_detect
 
 [ $API -lt 21 ] && abort "! Magisk is only for Lollipop 5.0+ (SDK 21+)"
 
+# Check if system root is installed and remove
+remove_system_su
+
 ui_print "- Device platform: $ARCH"
 
 BINDIR=$INSTALLER/$ARCH