repmgr: disallow node ids which are not positive signed 32 bit integers

Fixes GitHub #280

README.md

@@ -391,7 +391,8 @@ least the following parameters:
 
 - `cluster`: an arbitrary name for the replication cluster; this must be identical
      on all nodes
-- `node`: a unique integer identifying the node
+- `node`: a unique integer identifying the node; note this must be a positive
+     32 bit signed integer between 1 and 2147483647
 - `node_name`: a unique string identifying the node; we recommend a name
      specific to the server (e.g. 'server_1'); avoid names indicating the
      current replication role like 'master' or 'standby' as the server's

config.c

@@ -448,6 +448,10 @@ _parse_config(t_configuration_options *options, ItemList *error_list)
 	{
 		item_list_append(error_list, _("\"node\": must be greater than zero"));
 	}
+	else if (options->node < 0)
+	{
+		item_list_append(error_list, _("\"node\": must be a positive signed 32 bit integer, i.e. 2147483647 or less"));
+	}
 
 	if (strlen(options->conninfo))
 	{

repmgr.c

@@ -1946,9 +1946,6 @@ do_master_register(void)
 		exit(ERR_BAD_CONFIG);
 	}
 
-
-	}
-
 	begin_transaction(conn);
 
 	/*