Revert "Bump up buck version"

This reverts commit e743babd01c5cbfc3f580a4c77993bc7047d0846.

Change-Id: Ida34fc6fb6faba624b93b9b01a98e9f5d2bb4d33
diff --git a/tools/build/onos-buck b/tools/build/onos-buck
index d78d923..2e3a149 100755
--- a/tools/build/onos-buck
+++ b/tools/build/onos-buck
@@ -5,8 +5,8 @@
 
 set -e
 
-BUCK_URL="http://onlab.vicci.org/onos/third-party/buck-v2017.12.21.01.zip"
-BUCK_SHA="a8527763a314e64f6793067c1fedb60ec63d3cbc"
+BUCK_URL="http://onlab.vicci.org/onos/third-party/buck-v2017.11.30.01.zip"
+BUCK_SHA="8f8d807f591d72adfab212fd405237a398e2e836"
 
 [  "-U" = "$1" ] && shift && FORCE_UPDATE=True