remote.[ch]: parse_push_cas_option() can be static

Since 068c77a5 ("builtin/send-pack.c: use parse_options API",
2015-08-19), there is no external user of this helper function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

remote.c

@@ -2178,7 +2178,7 @@ static struct push_cas *add_cas_entry(struct push_cas_option *cas,
 	return entry;
 }
 
-int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
+static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
 {
 	const char *colon;
 	struct push_cas *entry;

remote.h

@@ -260,7 +260,6 @@ struct push_cas_option {
 };
 
 extern int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
-extern int parse_push_cas_option(struct push_cas_option *, const char *arg, int unset);
 
 extern int is_empty_cas(const struct push_cas_option *);
 void apply_push_cas(struct push_cas_option *, struct remote *, struct ref *);