* Fix oidentd spoofing regression

Only write to .oidentd.conf if there is something to write out.
This was introduced by the gcc warnings fixes.

src/dccutil.c

@@ -1027,8 +1027,9 @@ identd_open(const char *sourceIp, const char *destIp)
       if (ftruncate(fileno(f), 0))
         goto failure;
 
-      if (!fwrite(outbuf, 1, strlen(outbuf), f))
-        goto failure;
+      if (strlen(outbuf))
+        if (!fwrite(outbuf, 1, strlen(outbuf), f))
+          goto failure;
 
       //And make a record in the oidentd.conf to spoof the ident request from this port->dest-prot
       fprintf(f, "to %s from %s { reply \"%s\" }\n", destIp, sourceIp, origbotname);