Make CHANNELSDIR in smart empty, since this causes host contamination issues
on some RPM-based hosts on which smart is already installed.

[YOCTO #3881]

Upstream-Status: Inappropriate [embedded specific]

diff --git a/smart/plugins/channelsync.py b/smart/plugins/channelsync.py
index 3ba95ff..646d696 100644
--- a/smart/plugins/channelsync.py
+++ b/smart/plugins/channelsync.py
@@ -23,7 +23,11 @@ from smart.channel import *
 from smart import *
 import os
 
-CHANNELSDIR = "/etc/smart/channels/"
+# For now, we leave the definition of CHANNELSDIR empty. This prevents smart
+# from erroneously consider the  build host's channels while setting up its
+# channels [YOCTO #3881]. If this feature will be used in the future, CHANNELSDIR
+# should be set to a proper value.
+CHANNELSDIR = ""
 
 def syncChannels(channelsdir, force=None):