Add comment to force appveyor run
diff --git a/appveyor.yml b/appveyor.yml
index 46ce987..0b8615c 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -24,4 +24,5 @@
       OPENSSL64DIR: C:\OpenSSL-v11-Win64
 
 build:
+  # Launch the build using msbuild
   - ps: misc\build_picotls.ps1