Allow larger headers when scraping bandwidth data from mrtg pages

--- lib/datasources/WeatherMapDataSource_mrtg.php.orig	Fri Mar 22 09:26:41 2013
+++ lib/datasources/WeatherMapDataSource_mrtg.php	Mon Apr 22 14:32:24 2013
@@ -38,7 +38,7 @@ class WeatherMapDataSource_mrtg extends WeatherMapData
 		{
 			while (!feof($fd))
 			{
-				$buffer=fgets($fd, 4096);
+				$buffer=fgets($fd, 16384);
 				wm_debug("MRTG ReadData: Matching on '${matchvalue}in $matchperiod' and '${matchvalue}out $matchperiod'\n");
 
 				if (preg_match("/<\!-- ${matchvalue}in $matchperiod ([-+]?\d+\.?\d*) -->/", $buffer, $matches)) { $data[IN] = $matches[1] * 8; }