patch 8.1.0071: terminal debugger only works with the terminal feature

Problem:    Terminal debugger only works with the terminal feature.
Solution:   Make it also work with a prompt buffer.  Makes it possible to use
            on MS-Windows. Various other improvements. (closes #3012)

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    71,
 /**/
     70,
 /**/