bpo-43360: Remove dead initialization from parse_abbr function

Author: alexhenrie

Modules/_zoneinfo.c

@@ -1588,7 +1588,7 @@ static Py_ssize_t
 parse_abbr(const char *const p, PyObject **abbr)
 {
     const char *ptr = p;
-    char buff = *ptr;
+    char buff;
     const char *str_start;
     const char *str_end;