fold sysinfo into network

the backends are network backends

src/provision.js

@@ -25,7 +25,6 @@ const assert = require('assert'),
     safe = require('safetydance'),
     semver = require('semver'),
     settings = require('./settings.js'),
-    sysinfo = require('./sysinfo.js'),
     paths = require('./paths.js'),
     users = require('./users.js'),
     tld = require('tldjs'),
@@ -230,7 +229,7 @@ async function restore(backupConfig, remotePath, version, ipv4Config, options, a
             backupConfig.encryption = null;
         }
 
-        error = await sysinfo.testIPv4Config(ipv4Config);
+        error = await network.testIPv4Config(ipv4Config);
         if (error) throw error;
 
         safe(restoreTask(backupConfig, remotePath, ipv4Config, options, auditSource), { debug }); // now that args are validated run the task in the background