webrtc/dtlstransport: Add more debug. Rename category

Rename the dtlstransport debug category to webrtcdtlstransport.
diff --git a/gst-libs/gst/webrtc/dtlstransport.c b/gst-libs/gst/webrtc/dtlstransport.c
index d6b760e..9c06253 100644
--- a/gst-libs/gst/webrtc/dtlstransport.c
+++ b/gst-libs/gst/webrtc/dtlstransport.c
@@ -38,7 +38,7 @@
 #define gst_webrtc_dtls_transport_parent_class parent_class
 G_DEFINE_TYPE_WITH_CODE (GstWebRTCDTLSTransport, gst_webrtc_dtls_transport,
     GST_TYPE_OBJECT, GST_DEBUG_CATEGORY_INIT (gst_webrtc_dtls_transport_debug,
-        "dtlstransport", 0, "dtlstransport");
+        "webrtcdtlstransport", 0, "webrtcdtlstransport");
     );
 
 enum