patch 8.1.2158: terminal attributes missing in Terminal-normal mode

Problem:    Terminal attributes missing in Terminal-normal mode.
Solution:   Use "syntax_attr".
diff --git a/src/drawline.c b/src/drawline.c
index 15761bf..d702e9e 100644
--- a/src/drawline.c
+++ b/src/drawline.c
@@ -1517,7 +1517,7 @@
 		else
 #endif
 #ifdef FEAT_SYN_HL
-		if (has_syntax)
+		if (has_syntax || get_term_attr)
 		    char_attr = syntax_attr;
 		else
 #endif