change: config: handle NetProbe fatal error and run only if not offline

All errors returned from NetProbe are managed as fatal later.
Decide, connection issues are not fatal but bad configuration is.
Without this configuration errors are silently ignored here.

dnscrypt-proxy/config.go

@@ -469,9 +469,10 @@ func ConfigLoad(proxy *Proxy, svcFlag *string) error {
 		proxy.listenAddresses = nil
 	}
 	dlog.Noticef("dnscrypt-proxy %s", AppVersion)
-	NetProbe(netprobeAddress, netprobeTimeout)
-
 	if !config.OfflineMode {
+		if err := NetProbe(netprobeAddress, netprobeTimeout); err != nil {
+			return err
+		}
 		if err := config.loadSources(proxy); err != nil {
 			return err
 		}

dnscrypt-proxy/netprobe_others.go

@@ -3,7 +3,6 @@
 package main
 
 import (
-	"errors"
 	"net"
 	"time"
 
@@ -39,7 +38,6 @@ func NetProbe(address string, timeout int) error {
 		dlog.Notice("Network connectivity detected")
 		return nil
 	}
-	es := "Timeout while waiting for network connectivity"
-	dlog.Error(es)
-	return errors.New(es)
+	dlog.Error("Timeout while waiting for network connectivity")
+	return nil
 }

dnscrypt-proxy/netprobe_windows.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"errors"
 	"net"
 	"time"
 
@@ -43,7 +42,6 @@ func NetProbe(address string, timeout int) error {
 		dlog.Notice("Network connectivity detected")
 		return nil
 	}
-	es := "Timeout while waiting for network connectivity"
-	dlog.Error(es)
-	return errors.New(es)
+	dlog.Error("Timeout while waiting for network connectivity")
+	return nil
 }