patch 9.0.0068: build fails with tiny features

Problem:    Build fails with tiny features.
Solution:   Add #ifdef.
diff --git a/src/charset.c b/src/charset.c
index 2df64c9..8c6ac1c 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -960,10 +960,12 @@
  * Free any allocated item in "cts".
  */
     void
-clear_chartabsize_arg(chartabsize_T *cts)
+clear_chartabsize_arg(chartabsize_T *cts UNUSED)
 {
+#ifdef FEAT_PROP_POPUP
     if (cts->cts_text_prop_count > 0)
 	vim_free(cts->cts_text_props);
+#endif
 }
 
 /*
@@ -1023,7 +1025,9 @@
 	int		*headp UNUSED)
 {
     win_T	*wp = cts->cts_win;
+#ifdef FEAT_PROP_POPUP
     char_u	*line = cts->cts_line; // start of the line
+#endif
     char_u	*s = cts->cts_ptr;
     colnr_T	vcol = cts->cts_vcol;
 #ifdef FEAT_LINEBREAK