Fixed external javadoc URLs.

pom.xml

@@ -387,8 +387,8 @@
         <configuration>
           <overview>${basedir}/src/main/java/org/orekit/overview.html</overview>
           <links>
-            <link>http://download.oracle.com/javase/1.5.0/docs/api/</link>
-            <link>http://commons.apache.org/math/apidocs/</link>
+            <link>http://docs.oracle.com/javase/1.5.0/docs/api/</link>
+            <link>http://commons.apache.org/math/api-3.1.1/</link>
           </links>
         </configuration>
         <reportSets>