catch for NPE in image parser

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@6470 6c8d7289-2bf4-0310-a012-ef5d649a1542

source/net/yacy/document/parser/images/genericImageParser.java

@@ -79,6 +79,7 @@ public class genericImageParser extends AbstractParser implements Idiom {
         } catch (final IOException e) {
             throw new ParserException(e.getMessage(), location);
         }
+        if (image == null) throw new ParserException("ImageIO returned NULL", location);
         
         /*
         // scan the image