roomservice: Require python3

Change-Id: I08429fbc9380b3a1f04bbcc5116fedf3e2457747
diff --git a/build/tools/roomservice.py b/build/tools/roomservice.py
index 970ddca..0ba31d8 100755
--- a/build/tools/roomservice.py
+++ b/build/tools/roomservice.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Copyright (C) 2013 Cybojenix <anthonydking@gmail.com>
 # Copyright (C) 2013 The OmniROM Project