rfbsrc: Fix support for applevncserver

This server uses an unknown 003.889 protocol version. This patch fixes
the version validation in order to simply fallback to 3.3 as suggested
by the spec.
diff --git a/gst/librfb/rfbdecoder.c b/gst/librfb/rfbdecoder.c
index e6eb701..b3b01f5 100644
--- a/gst/librfb/rfbdecoder.c
+++ b/gst/librfb/rfbdecoder.c
@@ -347,7 +347,7 @@
   if (!rfb_decoder_read (decoder, 12))
     return FALSE;
 
-  g_return_val_if_fail (memcmp (decoder->data, "RFB 003.00", 10) == 0, FALSE);
+  g_return_val_if_fail (memcmp (decoder->data, "RFB 003.", 8) == 0, FALSE);
   g_return_val_if_fail (*(decoder->data + 11) == 0x0a, FALSE);
 
   GST_DEBUG ("\"%.11s\"", decoder->data);