Fixed checkstyle error

Author: lanseg

core/src/main/java/org/mapfish/print/output/JasperReportPDFOutputFormat.java

@@ -6,7 +6,6 @@
 import net.sf.jasperreports.engine.JasperPrint;
 import net.sf.jasperreports.engine.PrintPageFormat;
 import net.sf.jasperreports.engine.util.ExifOrientationEnum;
-import net.sf.jasperreports.engine.util.Pair;
 import net.sf.jasperreports.export.SimpleExporterInput;
 import net.sf.jasperreports.export.SimpleOutputStreamExporterOutput;
 import net.sf.jasperreports.pdf.JRPdfExporter;