STORM-151 : suppress the linux64 ref in install.xml and attempt to fix llkdumem.cpp linux compile issue

indra/llkdu/llkdumem.cpp

@@ -390,4 +390,4 @@ void LLKDUMemOut::put(int comp_idx, kdu_line_buf &line, int x_tnum)
 		free_lines = scan;
     }
 }
-*/
+*/

install.xml

@@ -841,13 +841,6 @@
             <key>url</key>
             <uri>scp:install-packages.lindenlab.com:/local/www/install-packages/doc/kdu-6.4.1-linux-20101118.tar.bz2</uri>
           </map>
-          <key>linux64</key>
-          <map>
-            <key>md5sum</key>
-            <string>f4e2e2b3440594527729a8c85119e508</string>
-            <key>url</key>
-            <uri>scp:install-packages.lindenlab.com:/local/www/install-packages/doc/kdu-5.2.1-linux64-20080926.tar.bz2</uri>
-          </map>
           <key>windows</key>
           <map>
             <key>md5sum</key>