Fix gdbclient to work with Python 3.

Test: gdbclient.py -r date
Change-Id: I10616c197dd50fe653e56c2e4c39e2371445c72b
diff --git a/scripts/gdbclient.py b/scripts/gdbclient.py
index 61fac40..5d4475a 100755
--- a/scripts/gdbclient.py
+++ b/scripts/gdbclient.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (C) 2015 The Android Open Source Project
 #