PDFBOX-6144: fix page parameter

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1931272 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

tools/src/main/java/org/apache/pdfbox/tools/PDFToImage.java

@@ -162,6 +162,11 @@ public Integer call()
             long startTime = System.nanoTime();
 
             // render the pages
+            if (page != -1)
+            {
+                startPage = page;
+                endPage = page;
+            }
             boolean success = true;
             endPage = Math.min(endPage, document.getNumberOfPages());
             PDFRenderer renderer = new PDFRenderer(document);