Linux DVB: remove dysfunctional "dvbt" scheme

It is redumdant with the preexisting dvb-t scheme and does not even
always select the correct delivery system. Also the failure mode is
much more confusing than a plain error input failure message, and
it is inconsistent with other delivery system names.
(cherry picked from commit 06a2a739e76f8c05776be0f84faef049a2505cec)

modules/access/dtv/access.c

@@ -232,8 +232,11 @@ vlc_module_begin ()
     add_shortcut ("dtv", "tv", "dvb", /* "radio", "dab",*/
                   "cable", "dvb-c", "cqam", "isdb-c",
                   "satellite", "dvb-s", "dvb-s2", "isdb-s",
-                  "terrestrial", "dvb-t", "dvb-t2", "isdb-t", "atsc",
-                  "dvbt")
+                  "terrestrial", "dvb-t", "dvb-t2", "isdb-t", "atsc"
+#ifdef WIN32
+                  ,"dvbt"
+#endif
+                 )
 
 #ifdef __linux__
     add_integer ("dvb-adapter", 0, ADAPTER_TEXT, ADAPTER_LONGTEXT, false)