Landmine: clobber to remove out/{Debug,Release}/args.gn

Landmine support was added back in
https://codereview.webrtc.org/1402923003/

BUG=webrtc:5070,webrtc:5123
TBR=phoglund@webrtc.org

Review URL: https://codereview.webrtc.org/1415453006 .

Cr-Commit-Position: refs/heads/master@{#10426}
diff --git a/webrtc/build/get_landmines.py b/webrtc/build/get_landmines.py
index 91b3e25..748da5d 100755
--- a/webrtc/build/get_landmines.py
+++ b/webrtc/build/get_landmines.py
@@ -38,7 +38,7 @@
   # dependency problems, fix the dependency problems instead of adding a
   # landmine.
   # See the Chromium version in src/build/get_landmines.py for usage examples.
-  pass
+  print 'Clobber to remove out/{Debug,Release}/args.gn (webrtc:5070)'
 
 
 def main():