Set am_sender to -1 until the end of the option parsing. This

lets who_am_i() output better values for the command-line
--filter/--include/--exclude options.

options.c

@@ -72,7 +72,7 @@ int numeric_ids = 0;
 int force_delete = 0;
 int io_timeout = 0;
 int am_server = 0;
-int am_sender = 0;
+int am_sender = -1;
 int am_generator = 0;
 char *files_from = NULL;
 int filesfrom_fd = -1;
@@ -825,6 +825,9 @@ int parse_arguments(int *argc, const char ***argv, int frommain)
 		}
 	}
 
+	if (am_sender < 0)
+		am_sender = 0;
+
 #if !SUPPORT_LINKS
 	if (preserve_links && !am_sender) {
 		snprintf(err_buf, sizeof err_buf,