HPCC-16271 Dafilesrv copyfile exception crash

Signed-off-by: Mark Kelly <mark.kelly@lexisnexis.com>

common/remote/sockfile.cpp

@@ -2991,7 +2991,7 @@ inline void appendCmdErr(MemoryBuffer &reply, RemoteFileCommandType e, int code,
     // RFCOpenIO needs remapping to non-zero for client to know its an error
     // perhaps we should use code here instead of e ?
     unsigned err = e;
-    if ((RemoteFileCommandType)err == RFCopenIO)
+    if (e == RFCopenIO)
         err = RFSERR_OpenFailed;
     reply.append(err);
     reply.append(msg.str());