build: Small fix to support Python3

Change-Id: I8e6218522ee9f03c9d9ee6357609f9003cc0cbad
Refs: #1302
diff --git a/.gitignore b/.gitignore
index 444b8db..a4d6499 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 .DS*
 .waf-1*
+.waf3-*
 .lock*
 **/*.pyc
 build/