patch 9.1.1496: terminal: still not highlighting empty cells correctly

Problem:  terminal: still not highlighting empty cells correctly
          (Yousef Mohammed, after v9.1.1489)
Solution: Use vcol instead of col

closes: #17632

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/drawline.c b/src/drawline.c
index afc0480..2388193 100644
--- a/src/drawline.c
+++ b/src/drawline.c
@@ -2774,7 +2774,7 @@
 		skip_cells = 0;
 #ifdef FEAT_TERMINAL
 		if (term_show_buffer(wp->w_buffer)
-		    && wlv.col == 0
+		    && wlv.vcol == 0
 		    && wlv.win_attr == term_get_attr(wp, lnum, -1))
 		    // reset highlighting attribute
 		    wlv.win_attr = 0;