Fix b/17116680: Change log level for unresolvable SIDs to FINEST"

Code Review: http://codereview.appspot.com/133730043
diff --git a/src/com/google/enterprise/adaptor/fs/WindowsAclFileAttributeViews.java b/src/com/google/enterprise/adaptor/fs/WindowsAclFileAttributeViews.java
index 66cf25e..f92c326 100644
--- a/src/com/google/enterprise/adaptor/fs/WindowsAclFileAttributeViews.java
+++ b/src/com/google/enterprise/adaptor/fs/WindowsAclFileAttributeViews.java
@@ -331,7 +331,7 @@
     } catch (Win32Exception e) {
       // Only the least significant 16-bits signifies the HR code.
       if ((e.getHR().intValue() & 0xFFFF) == WinError.ERROR_NONE_MAPPED) {
-        log.log(Level.WARNING, "Skipping ACE with unresolvable SID: {0}.",
+        log.log(Level.FINEST, "Skipping ACE with unresolvable SID: {0}.",
             ace.getSidString());
         return null;
       } else {