config-parser: Export weston_config_next_section

This symbol wasn’t exported from the weston binary, most likely due to
an oversight in 6e2c12496b, and because
internal modules can link against libshared.la directly it hasn’t been
found ever since.

This commit makes it possible for external modules to iterate over the
configuration file.

Signed-off-by: Emmanuel Gil Peyrot <emmanuel.peyrot@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Acked-by: Bryce Harrington <bryce@osg.samsung.com>

shared/config-parser.c

@@ -490,6 +490,7 @@ weston_config_get_full_path(struct weston_config *config)
 	return config == NULL ? NULL : config->path;
 }
 
+WL_EXPORT
 int
 weston_config_next_section(struct weston_config *config,
 			   struct weston_config_section **section,