config: pass signals to nm_config_reload()

Also react on SIGUSR1 and SIGUSR2, beside SIGHUP.
Only for SIGHUP actually reload the configuration from
disc. For the other signals only emit a config-changed
signal.

src/main-utils.h

@@ -44,6 +44,6 @@ gboolean nm_main_utils_early_setup (const char *progname,
 /* The following functions are not implemented inside nm-main-utils.c, instead
  * main.c and nm-iface-helper.c */
 
-void nm_main_config_reload (void);
+void nm_main_config_reload (int signal);
 
 #endif /* __MAIN_UTILS_H__ */