patch 8.2.3766: converting a funcref to a string leaves out "g:"

Problem:    Converting a funcref to a string leaves out "g:", causing the
            meaning of the name depending on the context.
Solution:   Prepend "g:" for a global function.
diff --git a/src/version.c b/src/version.c
index 083c111..0199aca 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3766,
+/**/
     3765,
 /**/
     3764,