patch 8.1.2266: position unknown for a mouse click in a popup window

Problem:    Position unknown for a mouse click in a popup window.
Solution:   Set v:mouse_col and v:mouse_lnum. (closes #5171)
diff --git a/src/version.c b/src/version.c
index 73a0c1f..9bb1436 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2266,
+/**/
     2265,
 /**/
     2264,