Update messages.json

Author: jchannon

messages.json

@@ -15,5 +15,6 @@
     "1.9.0-beta" : "messages/1.9.0-beta.txt",
     "1.9.0-beta2" : "messages/1.9.0-beta2.txt",
     "1.9.0-beta3" : "messages/1.9.0-beta3.txt",
-    "1.9.0-beta4" : "messages/1.9.0-beta4.txt"
+    "1.9.0-beta4" : "messages/1.9.0-beta4.txt",
+    "1.9.0-beta5" : "messages/1.9.0-beta5.txt"
 }