Auto merge of #40488 - alexcrichton:appveyor-debug, r=brson

appveyor: Turn down sccache logging

Let's not have it be quite so verbose

Author: bors

appveyor.yml

@@ -131,7 +131,7 @@ install:
   - handle.exe -accepteula -help
 
   # Attempt to debug sccache failures
-  - set RUST_LOG=sccache
+  - set RUST_LOG=sccache=debug
   - set SCCACHE_ERROR_LOG=%CD%/sccache.log
 
 test_script: