patch 8.2.5017: gcc 12.1 warns for uninitialized variable

Problem:    Gcc 12.1 warns for uninitialized variable.
Solution:   Initialize the variable. (closes #10476)

src/evalvars.c

@@ -2023,7 +2023,7 @@ do_unlet(char_u *name, int forceit)
 {
     hashtab_T	*ht;
     hashitem_T	*hi;
-    char_u	*varname;
+    char_u	*varname = NULL;  // init to shut up gcc
     dict_T	*d;
     dictitem_T	*di;
 

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    5017,
 /**/
     5016,
 /**/