patch 8.0.1812: the qf_jump_to_usable_window() function is too long

Problem:    The qf_jump_to_usable_window() function is too long.
Solution:   Split it in parts. (Yegappan Lakshmanan, closes #2891)
diff --git a/src/version.c b/src/version.c
index d8819ae..a2644f1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1812,
+/**/
     1811,
 /**/
     1810,