patch 8.2.1871: using %v in 'errorformat' may fail before %Z

Problem:    Using %v in 'errorformat' may fail before %Z.
Solution:   Set qf_viscol only when qf_col is set. (closes #7169)
diff --git a/src/version.c b/src/version.c
index 835de6c..48f7273 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1871,
+/**/
     1870,
 /**/
     1869,