patch 8.0.0354: test to check that setting termcap key fails sometimes

Problem:    Test to check that setting termcap key fails sometimes.
Solution:   Check for "t_k1" to exist. (Christian Brabandt, closes #1459)

src/testdir/test_assign.vim

@@ -15,7 +15,7 @@ func Test_let_termcap()
   call assert_match('t_te.*^[[yes;', execute("set termcap"))
   let &t_te = old_t_te
 
-  if !has('gui_running')
+  if exists("+t_k1")
     " Key code
     let old_t_k1 = &t_k1
     let &t_k1 = "that"

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    354,
 /**/
     353,
 /**/