patch 8.1.1340: attributes from 'cursorline' overwrite textprop

Problem:    Attributes from 'cursorline' overwrite textprop.
Solution:   Combine the attributes. (closes #3912)
diff --git a/src/testdir/test_textprop.vim b/src/testdir/test_textprop.vim
index 237eda9..dc229c0 100644
--- a/src/testdir/test_textprop.vim
+++ b/src/testdir/test_textprop.vim
@@ -645,7 +645,7 @@
 	\ "call prop_add(3, 15, {'length': 2, 'type': 'both'})",
 	\ "call prop_add(4, 12, {'length': 10, 'type': 'background'})",
 	\ "call prop_add(4, 17, {'length': 5, 'type': 'error'})",
-	\ "set number",
+	\ "set number cursorline",
 	\ "hi clear SpellBad",
 	\ "set spell",
 	\ "syn match Comment '//.*'",