Warn that gdbclient is deprecated in favor of gdbclient.py

Users of gdbclient might not know that a new and improved version exist
in the form of gdbclient.py.

Change-Id: I65243a8d25a1ecbe8ff734d0be4dbe40b50db4b2
Signed-off-by: Kevin Rocard <krocard@google.com>
diff --git a/scripts/gdbclient b/scripts/gdbclient
index acbbdda..74b6fd8 100755
--- a/scripts/gdbclient
+++ b/scripts/gdbclient
@@ -1,4 +1,7 @@
 #!/bin/bash
+
+echo "WARNING: gdbclient is deprecated in favor of gdbclient.py" >&2
+
 # TODO:
 # 1. Check for ANDROID_SERIAL/multiple devices