Fix appyveyor.yml

Change-Id: I6906170f7312641515e65cf24b70464c0e3b1586

Author: wesm

appveyor.yml

@@ -53,8 +53,8 @@ environment:
     ARCH: "64"
 
   matrix:
-    NOTE: clcache seems to work best with Ninja and worst with msbuild
-    (as generated by cmake)
+    # NOTE: clcache seems to work best with Ninja and worst with msbuild
+    # (as generated by cmake)
     - JOB: "Build"
       GENERATOR: Ninja
       CONFIGURATION: "Release"