Don't report .pyc file writes in sandbox logs

These are never fatal and often confusing.

Fixes #683.

Library/Homebrew/sandbox.rb

@@ -95,6 +95,10 @@ class Sandbox
       -k Sender sandboxd
     ]
     logs = Utils.popen_read("syslog", *syslog_args)
+
+    # These messages are confusing and non-fatal, so don't report them.
+    logs = logs.lines.reject{ |l| l.match(/^.*Python\(\d+\) deny file-write.*pyc$/) }.join
+
     unless logs.empty?
       if @logfile
         log = open(@logfile, "w")