build: Fix build error with python3

Change-Id: I2a35d66744330feefeb2c7f95a0f6e4e4c339358
Refs: #1956
diff --git a/.gitignore b/.gitignore
index 97873ea..b54981e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 .DS*
 .waf-1*
+.waf3-*
 .lock*
 **/*.pyc
 build/