close the private key file after reading it. patch by Wolfgang Nagele

git-svn-id: https://svn.verisignlabs.com/jdnssec/tools/trunk@111 4cbd57fe-54e5-0310-bd9a-f30fe5ea5e6e

src/com/verisignlabs/dnssec/security/BINDKeyUtils.java

@@ -118,6 +118,7 @@ public class BINDKeyUtils
       key_buf.append(line);
       key_buf.append('\n');
     }
+    in.close();
     
     return key_buf.toString().trim();
   }