patch 8.2.3777: spell file write error not checked

Problem:    Spell file write error not checked.
Solution:   Check writing the prefix conditions. (Bjorn Linse, closes #9323)
diff --git a/src/version.c b/src/version.c
index 03dee7e..1688db9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3777,
+/**/
     3776,
 /**/
     3775,