Fix: mb_strtolower function does not exists on all PHP versions.

Conflicts:
	htdocs/core/lib/pdf.lib.php

htdocs/core/lib/pdf.lib.php

@@ -835,7 +835,7 @@ function pdf_pagefoot(&$pdf,$outputlangs,$paramfreetext,$fromcompany,$marge_bass
 	}
 
 	// Show page nb only on iso languages (so default Helvetica font)
-	if (pdf_getPDFFont($outputlangs) == 'Helvetica')
+	if (strtolower(pdf_getPDFFont($outputlangs)) == 'helvetica')
 	{
 		$pdf->SetXY(-20,-$posy);
 		//print 'xxx'.$pdf->PageNo().'-'.$pdf->getAliasNbPages().'-'.$pdf->getAliasNumPage();exit;