Merge with 3.4
diff --git a/Tools/buildbot/external-common.bat b/Tools/buildbot/external-common.bat
index acc2b02..a58959e 100644
--- a/Tools/buildbot/external-common.bat
+++ b/Tools/buildbot/external-common.bat
@@ -9,6 +9,7 @@
 @rem if exist tcltk64 rd /s/q tcltk64
 @rem if exist tcl-8.6.1.0 rd /s/q tcl-8.6.1.0
 @rem if exist tk-8.6.1.0 rd /s/q tk-8.6.1.0
+@rem if exist tix-8.4.3.4 rd /s/q tix-8.4.3.4
 @rem if exist db-4.4.20 rd /s/q db-4.4.20
 @rem if exist openssl-1.0.1h rd /s/q openssl-1.0.1h
 @rem if exist sqlite-3.7.12 rd /s/q sqlite-3.7.12