Make compatible with JDK 1.4.

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/trunk@376489 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/mapred/JobConf.java

@@ -302,7 +302,7 @@ public class JobConf extends Configuration {
           itr.hasMoreElements();) {
         URL url = (URL) itr.nextElement();
         if ("jar".equals(url.getProtocol())) {
-          return url.getPath().replace("file:", "").replaceAll("!.*$", "");
+          return url.getPath().replaceFirst("file:", "").replaceAll("!.*$", "");
         }
       }
     } catch (IOException e) {