update version from 4.0.8 to 4.0.9

Author: prettycoder

lib/appoptics_apm/version.rb

@@ -8,7 +8,7 @@ module AppOpticsAPM
   module Version
     MAJOR = 4
     MINOR = 0
-    PATCH = 8
+    PATCH = 9
 
     STRING = [MAJOR, MINOR, PATCH].compact.join('.')
   end