Use span+css instead of font tag [ci skip]

core/Tracker.php

@@ -855,7 +855,7 @@ function Piwik_Tracker_ExitWithException($e, $authenticated = false)
 	
 	if(isset($GLOBALS['PIWIK_TRACKER_DEBUG']) && $GLOBALS['PIWIK_TRACKER_DEBUG'])
 	{
-		$trailer = '<font color="#888888">Backtrace:<br /><pre>'.$e->getTraceAsString().'</pre></font>';
+		$trailer = '<span style="color: #888888">Backtrace:<br /><pre>'.$e->getTraceAsString().'</pre></span>';
 		$headerPage = file_get_contents(PIWIK_INCLUDE_PATH . '/themes/default/simple_structure_header.tpl');
 		$footerPage = file_get_contents(PIWIK_INCLUDE_PATH . '/themes/default/simple_structure_footer.tpl');
 		$headerPage = str_replace('{$HTML_TITLE}', 'Piwik &rsaquo; Error', $headerPage);

core/testMinimumPhpVersion.php

@@ -74,7 +74,7 @@ if(!function_exists('Piwik_ExitWithMessage')) {
         @header('Content-Type: text/html; charset=utf-8');
         if($optionalTrace)
         {
-            $optionalTrace = '<font color="#888888">Backtrace:<br /><pre>'.$optionalTrace.'</pre></font>';
+            $optionalTrace = '<span style="color:#888888">Backtrace:<br /><pre>'.$optionalTrace.'</pre></span>';
         }
         if($optionalLinks)
         {