patch 8.1.1261: no error for quickfix commands with negative range

Problem:    No error for quickfix commands with negative range.
Solution:   Add ADDR_UNSIGNED and use it for quickfix commands.  Make
            assert_fails() show the command if the error doesn't match.
diff --git a/src/version.c b/src/version.c
index 5941c6e..d78ef3d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1261,
+/**/
     1260,
 /**/
     1259,