config: rename global config function

Rename this function to a more descriptive name since we want to use the
existing name for a new function.

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.h

@@ -382,7 +382,7 @@ int config_error_nonbool(const char *);
 #endif
 
 char *git_system_config(void);
-void git_global_config(char **user, char **xdg);
+void git_global_config_paths(char **user, char **xdg);
 
 int git_config_parse_parameter(const char *, config_fn_t fn, void *data);