patch 8.1.1945: popup window "firstline" cannot be reset

Problem:    Popup window "firstline" cannot be reset.
Solution:   Allow for setting "firstline" to zero.  Fix that the text jumps to
            the top when using win_execute(). (closes #4876)
diff --git a/src/version.c b/src/version.c
index 71901c9..5bde641 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1945,
+/**/
     1944,
 /**/
     1943,