rc: change PHP error reporting a bit more

* We can now see the errors we suppress.  E_WARNING is the one that
  should be zapped as soon as possible.

* According to the manual, display_startup_errors should not be enabled.

* Add ignore_repeated_errors to avoid multiple reports in e.g. loops.

src/etc/rc.php_ini_setup

@@ -131,8 +131,8 @@ html_errors = Off
 zlib.output_compression = Off
 zlib.output_compression_level = 1
 include_path = ".:/usr/local/etc/inc:/usr/local/www:/usr/local/captiveportal:/usr/local/pkg:/usr/local/opnsense/mvc:/usr/local/share/pear"
-display_startup_errors=on
-error_reporting = E_ERROR | E_PARSE
+ignore_repeated_errors = on
+error_reporting = E_ALL ^ (E_WARNING | E_NOTICE | E_DEPRECATED | E_STRICT)
 display_errors=on
 log_errors=on
 error_log=/tmp/PHP_errors.log